Packing for a family of five - are five carry-ons really the best idea?

Dani, you'll have to figure out what works for you. There's excellent packing advice under Travel Tips on the menu on the left of this page. Just consider that its not only packing for the airplane ride that you need to consider, but for how you are going to travel around - rental car, bus, train. All of those require you to manage and carry all your bags around, up stairs, cobbled streets, crowded trains, etc. Try walking around town and getting on a city bus or metro with all your bags, in the city where you live. The more you have, the harder it is to maneuver.

You can always buy bathroom essentials over there so no need for everyone bringing a bottle of their favorite shampoo. Nothing wrong with checking a bag, just don't let that tempt you into taking more than you need. Many people try and avoid checking a bag because that slows you down at your arrival airport. Five people will be pretty slow anyway.

We often checked our carryons (now wheeled)...I do even now whenever I can. So that makes it easy. The only bags that you should be concerned with is likely your 10 year old's bags. My daughter always had to be responsible for her bags, but at the younger ages, I was watching carefully, she was in charge of counting all the bags to make sure we had them all...from about the age of 4...to train her for the future. Your 14 and 16 year olds really need to be in charge of their own bags...they will be traveling on their own any minute now! So, really you are only responsible for your own bags and watching your 10 year old's. And you could make your 10 year old's smaller and split some back up clothes between your bag and your husband's bag, if needed. The small bags make it easy to move about. Everyone needs to be able to manage their own bags.

I like the idea that everyone needs to take care of their own gear/luggage. Kids seem old enough to help. On the other hand, if you don't have those bags and would have to buy them...I see your point. On the other hand, maybe nows the time to invest in a small carryon suitcase so they have it for future trips with the family or with friends.

Good luck! We took our 10 and 13 year old to London, Paris, Dublin and then to my grandmother's town in County Leitrim. Our family travel days continue and now they are 28 and 31!

Dani, I started taking each of my three (now grown) kids to Europe when they were 12-13-14 years old (though they traveled with me one at a time). From day one, they were each responsible for their own bags. I DID heavily assist them in figuring out what to pack and what NOT to pack (we made lists!) but then each pulled his/her own carry-on rolling suitcase and carried a small (school-sized) backpack from the moment we went out the front door of our home. We always used public transportation - trains and buses - and they each also became adept at reading train schedule boards, following maps, and doing mental math calculations of euros into dollars. They are each now seasoned travelers, and think little of finding cheap flights to Europe (or other places), booking, planning, and arranging travel for them and their families/friends. Think of this trip as not just THIS trip, but as a beginning of helping your kiddos become seasoned, independent world travelers! Yes, your 10-year-old will likely need more assistance than will the siblings, but it's still an exciting beginning for that child, too, to become independent and a skilled traveler. PS: re. getting luggage: read the luggage size restrictions of your airline, grab a tape measure, then take a look at what your local TJ Maxx (or equivalent) has to offer. Seconds stores may be great places to find the bags you need. Then, get some very colorful cloth ribbon (or very bright old t-shirt, cut up into strips) and tie big bows onto everyone's bags, so that they are color-coded for your family!

This sounds like the perfect trip to try out everyone using their own bag. No connecting flight, only one hotel change with a non-stop train.

We have our kids carry their own bags and the oldest is 10. We don't let the kids carry on personal items and only occasionally do either my wife or I carry one (usually a laptop bag if it is a work trip for me). So that would make 5 bags (sometimes 6 or 7 with a laptop) total.

I think the biggest challenge you will have is getting everyone to pack lighter.

DJ

The carry on and personal item for each is, in my opinion, the way to go. Agree with Wray that 14 and 16 year old young men are ready to be in charge of their own bags as it will be good training for later trips without you and / or your husband. Perhaps the 10 year old can be responsible for a smaller bag (back pack type?) that will be more suited to her physical size. Regardless of your final solution, don't put all your eggs in one basket -- split some of everybody's clothes in someone else's bag. If one (or more) bags gets gate checked (and it does happen regardless of size) and goes on it's own vacation, at least everyone will have enough to get by until the bag(s) catch up.

Hi Dani,

I have 3 kids who are recently 10, 13, and 15 (so in summer 2017 they were 9, 12, 14). We always take 5 bags and everyone is responsible for their own, with the 9 yo getting some help. We traveled to Europe last year for 5 weeks and 3 countries using 4 Osprey 46's and the 9 yo used a backpacking pack slightly smaller than the Osprey. We find that 5 individual bags is far easier than, say, 2 larger, which we used to do until we got smarter ;)

Here's a few things that were in the bags: 1 pair of long pants, 1 rain jacket, 1 light jacket, 1 long sleeve, plus enough summer clothes to last for 5 days (so 5 t-shirts, 5 underwear, and 4-5 shorts/skirts). In addition to this the 9 yo brought 2 medium sized stuffed animals, my husband and I brought computers, and we also had camera, kindles (3), notebook, paperwork, etc etc. We divided the toiletries among the two bigger kids and the adults. Husband and I wore this bag as our day-bag/purse:

https://www.ebags.com/product/pacsafe/venturesafe-150-gii-anti-theft-cross-body-pack/250552?productid=10233504

This could be swung around front so was easily worn with the backpack on our backs and made access to passports and money very easy and safe. In this bag I could even fit my light rain jacket, and I also carried this bag in the day-pack/purse, which folds into the size of a fist and weighs 68g. Thus I had something to carry purchases or groceries when needed but didn't have to carry a backpack on outings:

https://www.trekkinn.com/outdoor-mountain/sea-to-summit-ultra-sil-day-pack/135906753/p?utm_source=google_products&utm_medium=merchant&id_producte=2287961&country=us&gclid=EAIaIQobChMItOuw3ouF2QIVWJR-Ch378giaEAQYAiABEgLnE_D_BwE&gclsrc=aw.ds!

The kids didn't need a day pack/purse.

Having carry on's rather than checked luggage saves a lot of time on both ends of the flight, and is far easier to mange on trains, buses, etc. In general, we now always use the Osprey's when we travel.

HTH,
Jessica

You need to focus on the train portion of the trip. Can everyone handle their own bag? I would assume so. Taking a couple of larger bags on the train will be a hassle.

The kids are old enough to manage their own luggage. Read Rick's advice about packing, although I pack significantly lighter than the grand wizard of travel.

Agree that it's your choice -- but as you noted, you will have only TWO locations so your bags will only have to go airport to Paris rental, Paris rental to Eurostar, Eurostar to London rental, London rental to airport. Most/all of these could be done by taxi, without luggage hassle, at a price comparable to public transit for 5. And the Eurostar won't have any 5-minute connections between trains.

My husband and I check bags on all plane trips even though we use carry-on size rollers. The time spent waiting for bags is usually minimal -- sometimes the bags are waiting for us after we get through immigration, find bathrooms, and walk the long trek through the airport. For us, the advantage of smaller bags is ease of handling when we take multiple trains on longer trips.

Either way, have a great trip. Just make sure that you and your family hand-carry your crucial items -- medications, passports, credit and debit cards, and a change of underwear in case your bag(s) get delayed. And flying home, you don't even have to worry about the last item.
EDIT: For full disclosure, I DID do carry-on when taking my 12-year-old to England 25 years ago, and she handled her own carry-on bag, as she did on later trips when we checked.

If you decide to combine clothes in a checked bag, I would recommend color-coded packing cubes--a different color for each person. That way, each person can easily find his clothes in the shared bag. BTW after years of carry-on only, I now check a bag that I can manage on my own (I am petite and 71 yrs young). Getting thru security, using airport restrooms, boarding, etc. is so much easier now and I have not had a lost or delayed bag YET. I know some will chime in that it is just a matter of time! Happy travels!

Two years ago we traveled with our son's family for nearly a month, visiting Paris and London for one week each. The granddaughters were 10 and 13 at the time. Each family member had a 21" carry on as well as something for their personal item. It worked really well, no issues.

Edit: we had laundry opportunities at the places where we stayed. The girls were so light in their packing that they visited thrift stores in Paris and bought a couple of "French outfits" each. In addition to our similar climate in Paris and London, they were also prepared for a week's worth of weather in Istanbul and the Isle of Skye, Scotland. I was very proud of them for their packing choices and managing their own luggage.

I've traveled with 3 teens. Everyone managed their own bag. I think the 10 year old could handle this. Since you are staying in apartments with washers you really won't need to take much. I would think you could easily get by with just 4 carryons. I agree with other posters that even though you are not very nomadic handling smaller bags will be much easier than a couple of large bags.

It depends how big the checked bags need to be. A very large bag is hard to manage on a train and on public transit. If you mean combining everything in 2 or 3 24inch rollers, that could be fine. If you are thinking one or two very large bags - reconsider. I suppose if you are taking taxis to your hotel and your only public transit with the bags would be the Eurostar it might be OK but still annoying. A large bag won't fit near your seat so you'd need to use the luggage rack at the back of the train car.

As for personal items - make sure everyone can carry their own easily. Backpacks or messenger bags work well, or a larger purse for women. I prefer messenger bags, but thats preference, either works OK.

Your key will be making sure ALL your stuff fits in the suitcases and personal items you have chosen (be they bigger or 5 smaller ones). I know what you mean about having misc extra bags for shoes and toiletries on a road trip. Won't work on a trip like this - you won't have a car and will have to carry it all yourself.

I travel with 4 - husband and 2 kids, age 11 and 8. My husband has a messenger bag and a carry on, I have a purse and a carry on, one of the kids has all his stuff in a carry on backpack (actually personal item sized, he's small) and the other has all his stuff in a carry on roller. No personal items for the kids - their books, water bottles, and ipads for the plane are in a large ziplock in their carry on and they just take it out when boarding and put it back when off the plane. They don't use a day bag when out and about, so it works. That's 2 less bags to worry about.

You've gotten a lot of good information as to which way to go. Ultimately, it is up to you.

The big question is how are you traveling between airports/trains station and accomodation? If by public transit, then carry on bags will be much easier. I've seen too any people chase after big bags on local trains. If you are taking a cab or a hire car, then the bags just have to go in the trunk.

With the Eurostar, you are responsible for your own luggage. There are no checked bags.

If you do decide to check a bag or two, make sure you have the basics for a couple of days in the carry ons you're taking just in case the checked bags get rerouted.

I have done it both ways and I can say for me, a family of 1, I will hopefully never have to check a bag again.

Pack light! For two weeks you don't need a lot. Everyone has their own bags that meet the airlines carry on requirements. Only check bags you are prepared to not see again. There are many tips on this site and others on how to pack. Here is one I like: https://m.youtube.com/watch?v=PDn9l20NlWw

I agree with DJ. You will be changing locations only once so the amount of luggage won't be a problem when moving around. The airlines usually give you at least one checked bag per person but that is a lot of bags for 5 people. You can pack a lot into a non-rigid carry-on. I was able to pack 10 change of cloth but it sure made the carry-on heavy. What worked for us last summer was for each one to take a carry-on and every 2 people could check one extra bag. You will be able to do laundry the first day you arrive at Paris and then you'll be set till you go home. Have fun!

A relatively large bag should not be a problem on the Eurostar. Up to two large bags per person are allowed (or one for a child under 12 on child's ticket), maximum 33 inches long, and a small personal item. Luggage racks are sized that way. And some Eurostar departures make no stop between London and Paris, so there's little chance for your bag to depart the train without you. Paris Nord used to have fancy escalators (that even took luggage carts) up to the Eurostar boarding area and probably still does.

The way that you've simplified your trip seems pretty smart. But I do think that whomever is lugging other people's stuff need not have that burden.

This is a bone of contention for me. Aircraft are not designed to accommodate the amount of carry on luggage that is common now and it is causing endless problems with insufficient storage and flight delays whilst cabin crew try to find space to cram all the luggage in.

On my most recent flight I observed a family of five board the aircraft right at the end, all of them with a large 'carry on' bag, even the toddler! Suffice to say there wasn't room for all the bags where they wanted them and the crew spent a significant amount of time re-arranging and crushing other passenger bags to try and fit them in. When we travel as a family or even as a couple we take one or two large suitcases and check them in. The only occasions when I take a carry on is if I'm travelling solo for a weekend and even then it's a small duffle bag, a quarter of the size of many of the wheeled suitcases that people bring on.

The airlines are as much to blame for introducing additional fees to check luggage but I consider it a small price to pay and courteous to my fellow passengers.

If you're staying in one place for a week then you're not going to be unpacking and packing and moving on every other day so a large suitcase isn't really an issue, if anything it's easier. I say go large and check it in.

I no longer do carry on only. My bag would qualify, but Tykewife's won't. Both bags are wheeled which to me is a must since we use public transportation and usually end up walking at least a couple of hundred yards to where we stay.

Snce you are only staying 2 places and taking one teain, donwhatever you feel comfortable with. As a general rule, each person should take his own bag.

The thing I love about asking questions on these forums is the variety of the replies. All excellent food for thought - thanks to all who took the time. Still not sure what solution is right for us, but I've got a lot of ideas now. A practice run on our local city buses might be an excellent adventure!

Dani, do your boys have backpacks for school? Every kid here carries one, and they'd work fine as luggage. And the boys are already used to carrying them, so it's no big deal. I doubt each one needs a personal item, either.

I vote for the one large and one small suitcase ( only if they have wheels) checked. let the boys have a backpack for personal item and have a change of clothes in that. Getting 5 people thru security is enough- I can barely keep track of my stuff. I would rather just have to count 5 people , 5 backpacks as we go thru security- get on the plane, leave the plane. Also, at the end of the day, even if each boy is responsible for his bag, if something is lost, forgotten etc, its you who is gonna have to pick up the pieces. have fun. My son at 10 loved the Tower of London and the Transport Museum and we both loved just riding the double deckers buses and the London Eye.

We are a family 4 and have done a lot of train travel on trips to Europe & Japan. Last trip we took 3 carry ones (my daughters share 1 carry on). My husband has a backpack since he has to carry his work computer. My daughters and I share the personal item--1 small wheeled tote that fits under the plane seat. I'm sure your kids are like mine, all they need is their iPad minis and some headphones. iPad serve as their game, music, and Kindle devices.

But I won't lie. We still seem to end up with extra stuff. We often have a hot food bag, cold food bag, and/or room temperature snack bag. And maybe Tote containing light jackets, small rain pouches or umbrellas, and water bottles. Maybe not all those bags all the time but we can easily have 3 extra totes.

We still tend to be very mobile, but imagine that with 3 boys you're going to want to have extra food, water, and electronics.

Tip: bring extra external battery chargers

Work on the assumption that each set of clothes will last a day, although you may also want to change for the evening, depending on what you are doing.

Personally, I don't want to spend valuable time on a 2 week holiday washing clothes (or if you are in a hotel paying someone to do this and hoping that I get all the items back or they haven't shrunk anything), so I would pack sufficient clothing for the entire trip. In my experience, you can only pack a weeks clothes in a carry on, so check in bags are the way to go, particularly as you aren't undertaking lots of different accommodation changes. Dropping bags and picking them up at the airport adds very little time to your journey. All bags have wheels these days, so moving them around isn't difficult.

Personally, I don't want to spend valuable time on a 2 week holiday washing clothes

Okay this might sound bad but on our 5-6 week Europe or Japan vacation I'm with my husband and kids 24/7. My family is pretty easy going and we travel great together. But I loved my time in laundry mats. I have my husband take the kids somewhere and laundry mats were my downtime.

Once in Paris I let my husband do the laundry. When he came back he said "now I see why you never complain about washing the cloths."

But in Japan we only did Airbnb and only rented apartments with washing machines.

Yes carryons really are the best option. You will have to tote all your bags by, taxi train and bus anyway. Toting them in the airport is much easier than that with the limited but awful exception of security.

To help your boys, make sure their personal items are backpacks and that they don't take them off until they are in the apartment or seared on train or plane. You can probably consolidate the kid's packing so that their personal items fit inside their carryons. Take the personal items (entertainment out on the plane and on Eurostar. Otherwise they can be in the personal item during transit.

My answer would be different if you already had the suitcases. But, since you don't have 3 carry-ons, I would say just pack the checked luggage, have all of your kids wear their school-size backpack with stuff for the plane and 1 change of clothes. And enjoy your trip!

5 small bags, definitely. When we first took our girls to Europe to visit family we decided to taken a short trip to Prague, Vienna and Budapest. To make life easier, so we thought, we took one large bag for all four of us. Big mistake for the following reasons

Too heavy, only husband could pick it up
On the overnight train, couldn't find anything we needed quickly - no packing cubes
On the regional trains, didn't fit near our seat
While walking in Budapest from the train to our hotel, the handle broke. Yes we could still wheel it, but couldn't pick it up easily, especially on the stairs - my girls had never heard their father curse so much.
In Vienna a friend picked us up, could just about squeeze into her trunk

Our next trip, we took the overnight ferry down the Croatian coast, we all had our own, small suitcase. We moved around to a few islands with no suitcase problems, and not one curse word uttered. The girls had to only bring what fit so there was no overpacking.

P.S. Even if we have carryon size only, we still check our bags, especially if we have a connecting flight. We don't want to jerk around with our bags during the stopover.

I think all the dogma around how the only way to travel smart is carry-on only is misguided. (That said, as in all things travel, to each their own). I travel with an American-size carry-on and check it (22" Eagle Creek Tarmac), and can get by doing laundry only once in a two week trip. It's way easier moving from place to place, especially since I am the who gets to carry my wife's bag up stairs as well as mine. She will pack a 25" bag to the limit of what they'll accept, but a 22" tops out around 30 lbs. The impetus for downsizing for us was the size of rental car trunks. Also the reason it takes the better part of an hour to board a flight is because of oversized carry-ons (luckily less of an issue for overseas flights), and I don't like to stress over weather there will be space and if my bag is really small enough. (Note European carry-on size is smaller than U.S. Planes used for connecting flights often have very small bins, but that won't be an issue for you on this trip, sounds like). Sounds like you are moving only once during your trip, but still a good idea to not over pack. Waiting an extra 20 minutes for the luggage is probably less than you'd spend hunting down toiletries. For me, I am very picky about dental hygiene products and don't like the idea of buying mouthwash in a country where the label is in a language that I don't speak. The determining factor for you probably has more to do with logistics of traveling with kids, about which you know best. Pack light but check the bag is my preference.

"I think all the dogma around how the only way to travel smart is carry-on only is misguided." It's not my dogma...but I've traveled enough to know what's best for me and that is travel light and take my luggage as carry-on. I've never lost my luggage nor had to wait at an airport for hours(?) hoping it's found and might arrive on a subsequent flight and not significantly delaying my departure. Surely most people checking luggage never encounter a bad experience...I have and also made connections from delayed flights that were impossible with checked luggage. Do what works best for you...I know what works best for me. Amen.

My parents were world travelers. And I remember my father lifting a huge bag for my mother who never heard of Rick Steve's Packing List. Big bags affected my father's health for a few weeks after returning.
My family rules are that everyone can take whatever they wish--as long as it fits in a 21 inch rolling carry on bag. They have to be able to carry their bag 2 miles.
I no longer carry bags for anyone, and I never check a bag with any airline.

Three things that I haven't seen mentioned here:

• European apartments are notorious for having dryers that don't work very well at all. You'll often have a washer/dryer combo., which limits how quickly you can get laundry done. And on top of that, the washers tend to be quite small and shockingly slow. Do not wait until everything you have with you is dirty to do some laundry; you may not have anything clean and dry the next morning. Both London and Paris can be quite damp, and that will slow down air-drying.

• Anyone who walks around with electronic gear or a wallet in a backpack should be prepared to have it stolen. The pickpockets are professionals; tourists are amateurs. Do not assume that because there are five of you, someone will notice a pickpocket attempt.

• It is possible for both London (especially) and Paris to be quite cool in the summer. Do not assume it will be sweltering (though it could be). The day before departure, check weather projections for both cities. What you see for London should be fairly accurate, temperature-wise. In my experience the forecasters have a lot more trouble predicting when it will rain. The Paris info will be of uncertain accuracy so far out, but it doesn't hurt to look.

As for the rest: I would definitely use this trip (though it is logistically simple) to introduce concepts that will pay off on future trips. Concept No. 1 is packing light.

Not being a fan of wasting money, I would use the luggage I had as long as it's not larger than 24" or so. That size is already getting a bit awkward to maneuver up the narrow steps onto trains. If you decide you need some new suitcases, pay particular attention to the comment that European carry-on limits are lower than ours. Do not assume that a bag that just meets US limits (and you must measure; do not trust the manufacturer's label) will be legal on the flights within Europe that you are likely to take in the future.

There are some items readily available in the US that I haven't found in Europe. One is small sizes of solid deodorant--in fact, I usually only find roll-ons. Pepto-Bismol seems not to exist, nor do high-zinc-content lozenges (which may help adults who are developing colds). One hopes the latter will not be needed in mid-summer, especially on a short trip, but with a different environment, you never know.

There are so many ways to pack. Only the 10 year old needs help here. Consider packing cubes in a bright color. Put the child's stuff in packing cubes and pack in everyone else's bags to eliminate a bag. Just bring 1-2 small duffle/tote/backpack type bags as flight bags for the family. Not everyone needs a flight bag. Daypacks can be packed in luggage and pulled out once you reach your hotel. Be strict with your kids and don't let them pack too much stuff. Maybe make a packing list for them to follow. Packing cubes in bold colors are a big help in family packing.
P.S. RS Appenzell pack on sale makes a good family daypack for 2 - 4 people. Teenagers need to wear their own daypacks on trip. Don't be their mule. Also, carry a first aid kit (I can give you more details in another post.) and packets of flushable wipes available near the toilet paper at most grocery stores.

Thank you, Emma. I'll be back in the UK later this year and I'm glad to know I just didn't look in the right places for the deodorant. I carry a little Pepto-Bismol with me, so that's never been an issue.

High-zinc lozenges are different from zinc supplements, and I've checked with pharmacists in a bunch of European countries with no luck; they don't even seem aware that such a thing exists. Incidental zinc is sometimes present, but not the amount you need to stop the cold symptoms in their tracks.

I'm not sure there is any such thing as a really flushable wipe. Especially for European toilets. I'd proceed with care on those.

I'm on the side of packing light and using carry-ons. Good practice for the kids for future trips.
Also, I think the logistics are actually easier. As you leave the plane, adults say, "Get your 2 items everyone!"

You mentioned trying to rustle up 3 extra carry-on bags. Check out 2nd hand stores such as Salvation Army, Goodwill, or whatever they are called in your area. And, one of mine IS a backpack and those are easy to find.

Also from another thread where you asked about teens in Paris: my kids also liked the free Paris tours (and they benefit from the mini-history lessons), both are good:

http://www.neweuropetours.eu/paris/en/home#

https://www.discoverwalks.com/tour/type/free-tours/?town=paris-walking-tours

Have fun. (Thanks for your kind words in the other thread.) -Shoe

Following up on acraven's comment about dryers -- sometimes the "dryer" is more appropriately called a "drying rack" . I carry three plastic coathangers and two pants hangers for the two of us, and that seems to work well for hanging damp clothes to dry reasonably wrinkle-free in the closet. (The centrifuge cycle on the washer really removes excess water.) And socks and underwear dry fine on the rack if you give them 24 hours.

Washer dryers are washing machines with an integrated dryer, does the job well even if it leaves your clothes very creased. If the room description states washer/dryer then this should be what it means. European washing machines take longer to wash clothes because they're not as harsh as American top loader styles. They also run on cold water, heating the water in the machine to the desired temperature. This apparently helps the enzymes in the washing powder work better but who am I to know. They also use significantly less water than top loader machines.

When I first experienced an American top loader I thought there must have been a problem as the cycle was over in about 15 minutes. I must admit those paddles do look like they're a lot harsher on the clothes than a front loading drum. I only ever use the drying facility on my machine for small items or towels, everything else dries on the line outside or on a rack indoors but if there's insufficient heat or airflow you do run the risk of clothes developing that awful musty, damp smell.

I agree with Sun Baked in Florida. The 10 year old is the primary concern. The rest of you can probably get by with a carryon and personal bag, if you follow the Master’s “packing light” mantra.

With so many of you traveling together, while I usually advocate carryon only, depending on your connections and airlines, you might consider one “shared” checked bag such as a lockable duffel for extras and stuff you bring home. You could also use this as a primary bag for the 10 year old’s clothes, with one change of clothes in a mid sized backpack for him or her to carry on in case of loss.

As for the carryons, definitely adhere to the international carrier rules re: weight and dimensions. The best places to find new, cheap bags are TJ Maxx, Marshall’s, and the like, though you may be doing a lot of shopping depending on how many bags you need to buy. If you don’t care about new, try Goodwill. (They’ve received many of my gently used bags over the years, and I suspect the same of many others on these forums;).

Sounds like a great trip and a once in a lifetime adventure for your kids. Enjoy!

We started traveling to Europe when our boys were 8 and 10 - first trip we took one large suitcase and one smaller suitcase for all of us - and promptly learned the error of our ways!
I strongly recommend each person having their own bag - as other posters have noted, you can find inexpensive bags at second hand shops, Costco and ebags - I think our first carry ons from ebags were about $50 and my boys still use them -14 years later.
Things are smaller in Europe - cars, rooms, etc., etc. and wheeling a large suitcase onto a train is not a terrific idea - I almost missed my train to Avignon from Paris due to a family trying to get several large suitcases on the train!
As for doing laundry on the trip - if you have a washer, it's not a big deal - and gives you an excuse for a little downtime - always good on a trip.
For Paris and London for two weeks you can easily get by with a carry on each and even a "personal item" each - my boys had no trouble managing their carry on and backpack and it definitely made getting from point A to point B easier.
London and Paris are wonderful - have a fabulous trip!!!

Dani

Here’s some inspiration for you from the Big Red Kitchen.
It’s one of my favorite traveling family posts. Her kids are younger than yours.

My opinion is use backpacks for the kids, especially if you already have school backpacks. The kids don’t need much clothing. Have them wear their jeans and pack a pair of pants and a pair of shorts. Make sure they each have a sweater and jacket. Two pairs of shoes, including the ones worn.
Many toiletry things can be shared. But the boys won’t need many toiletry items. Leave the mega first aid kit at home, along with mosquito stuff.

Everyone is responsible for their stuff. I’d advise backpacks only for the kids, no personal items. If you want a personal item get the dollar store string backpacks that they can stuff into their main bag. That way they have their games etc at their seat.
You keep the passports in your personal item.

Do laundry once a week, just like home. Rinse some things in the sink as needed.

My concern with a single suitcase is the size and weight. And what happens if it gets lost? The whole family is affected. Big suitcases are a liability when moving around and also in smaller accommodations.

I found a carry on roller at walmart for $15. It weighs 3 1/2 pounds. Cheap but held up in three countries and flying across us. Also Rick Steves Euro bag fits right over it. Don't feel pressured to take the best.