One carry-on bag for two months travel?

It can definitely be done. You don't really need any more clothes for a 2-month trip than you would for a 2-week one. (You will, however, get tired of them by the end!) Choose things that mix and match, in travel-friendly fabrics that wash easily and pack small. Mostly lightweight things and layer if it is cold. My basic list is: 2 pr capris, 2 pr long pants (lightweight, not heavy jeans); 2 pr. shorts (we hike a lot); 1 or 2 light rayon skirts or long dresses to layer with a sweater; 4 short or sleeveless T's; 2 long-sleeve shirts; 1 light jacket. For Switzerland I add a fleece, rain jacket, and hiking boots. This fits easily, along with toiletries, lingerie, etc., in my 22' carryon. If you need more---buy it there!

If you didn't need your laptop, you probably could manage it. However, I think you'll appreciate having a day pack along with your carry-on bag even if you left your laptop at home. This allows you to Leave your main bag in your room when you head out for the day. Just be sure you buy small locks to secure the zippers so the pockets are not accessible to thieves coming up behind you. The Civita and Appenzell day packs are sold in the Travel Store on this site. The Appenzell is big enough to hold your laptop, thus making it a little more versatile than the Civita.

I think two months requires about as much stuff as two weeks--less, if anything, since you will not want to drag around an ounce more than you need on such a long voyage. So be disciplined and travel light, and have a great trip!

Just remember that if you are flying from or through the UK to any other location that you'll be limited to ONE (not 1 + purse) carry on (see www.baa.co.uk size reqs) and they are strict.

Given that you'd probably have to check something in UK or if you are on a small plane/crowded flight and you do not want to risk having to check your laptop & valuables, you probably want to go with a laptop bag/backpack and another bag. You can always put an overnight's worth of clothes in your carry on in case the checked bag goes astray briefly.

The only other issue you might want to consider is that the UK and Switzerland are about the two most expensive places in Europe, so not great places to buy new clothes. Of course you are limited to your one baggy of liquids/gels, so you'd have to be willing to get those in each location and not have allergies etc. that require a certain brand of tolietry.
Have fun!
Kate

My daughter and I each used Rick Steves' 21-inch Roll Aboard and each had 2 compartment day back back for 8 weeks.

We each took:
4 outfits
4 sets unders
3 pairs shoes and socks (Birkenstocks bought there)
short light fleece jacket
Rain poncho
Umbrella
Rick's King size micronet travel towel
European electrical adapters
Silk Sleep Sack
Travel clock
2-travel clothes line (Ricks's)
Packing Cubes
9 pounds of Digital Camera, Movie cam, rechargers, batteries
Toiletries
Neck pillow
Etc.
We took Rick's advice and traveled light and it payed off.
We mailed packages home about 4 times.

Hey I picked up the Weekender from Ebags. It has plenty room to pack all your clothes and a large outer pocket that holds my journal, travel docs, maps and laptop. I too travel for business and pleasure at the same time so something that works well for both was important. I found it to be plenty roomy, sturdy and cost effective at $49 USD and free shipping. I'd say you might want to pick up a small packable daypack for hauling some stuff around during the days when not carrying your full on bag. I found this bag from Kiva that packs into it's own outer pocket so it was quite useful since it was only a backup. Find what suits you best and is good and sturdy. Remember convertible carry-ons like the RS bags, the Weekender I use or some others will provide you with plenty room, good value and versatility that you'll need on a longer trip like that. Safe Journey!

Thank you all for your advice! I do have a backpack but it isn't square, and that is denying me the tiny bit of extra space I might have with a square bag. Months ago I purchased luggage, and a shoulder bag for the lappy, and the backpack. I wasn't sure what to use. Now I wish I hadn't bought any of them, but had purchased a squarish backpack that could still protect my laptop. I even hand-painted my checked bag so I'd see it amongst all the other bags (I'm an artist... couldn't help but paint it). Now it looks as if I will be selling it on ebay to help recoup my losses on luggage. Should have found this site first.

I haven't given up on the one-bag thing yet... I will find a way to eliminate more excess and somehow get it all packed inside the backpack. Or I'll have to spend out more money and buy another backpack that will work better. :)