Luggage !

I always travel with a carry on only. As a skier, I had learned to dress in layers, so for cold weather I didn't need to add much.
When I went to Germany for two weeks starting Christmas day, I wore a down parka and had a sweater underneath for really cold days. I wore the down parka on the plane, so it didn't add anything to my carry on weight, and I always pack the sweater anyway. I also wore thermal long john bottoms, which are light weight to pack. I did buy a knit hat the first day because my head was cold.

I was fine even with temperatures in the teens (F).

By the way, our trip was to the higher elevations in Germany (Black Forest and Bavarian Alps).

Ye of little faith! (Joking here.). You can do it! If you have bulky Winter clothes - consider 1 single 24" suitcase and 1 smaller bag that is either a backpack or can ride on top of the suitcase (trolley strap). You have a lot of choices. If you can drag it - you can bring it. (Think up and down train steps, old staircases, etc..). I have traveled both carry-on and with larger cases.

I've done 6 RS tours with a 22" roller (which I check and usually include trekking poles) and a slightly smaller rolling backpack (which I carry on and use for a CPAP). As long as you can handle your luggage without help, you will be fine.

Yes, we brought just the RS rolling carry on suitcase for our RS tours several years ago. I remember when we first signed up, and the information said to bring only a carry on, we both wondered how we would ever be able to do it! Since that first trip, we've never traveled with checked luggage, except to bring food, etc. for an extended time in Hawaii.

When the size for carry on suitcases changed to a smaller size for airline requirements, we bought the new carry on size and added a small backpack, each. We've used that method for all of our trips to Europe (typically three weeks) each year.

For colder weather, I have packed the cheap grocery store tights to wear under my pants, and a very thin thermal undershirt. I also brought a long-sleeve T-shirt. All of that was perfect for some cold days in Switzerland. Otherwise, I just layered as needed. Don't forget a pair of lightweight gloves.

Is your 8 day RS tour a one or two city tour? This would be as opposed to a multi city, multi country tour. I believe for the former you don't travel to and from many hotels( which is easier to do with less or smaller luggage). If you are staying in one hotel for longer time you can get away with more or larger luggage because you aren't lugging it around as much.

With only 8 days you should be able to use a 22" roller bag and some sort of daypack. Try practice packing one with the warmer clothes you would like to take and see if it works. My packing light is taking a 22" and I do check it on the airplane. Mine is also the kind that can expand a couple of inches if needed using the zipper. If I was staying in one or two places only and needed more room, I would consider a 24" or whatever the next size usually is. If you have no help with your luggage, I do find lugging around a heavy, larger suitcase is harder.

What Lee said about layers and wearing your heavy coat/boots onto the plane (and train or bus.) I once tried a 24" suitcase for the extra space, but found that I filled the extra space with so much (unnecessary) stuff that I couldn't lift it easily. Back to using a 22" rollaboard (checked) plus personal item (Euro tote with strap for carrying on the rollaboard handle)
Look for light-but-warm layers : merino wool or cashmere sweaters instead of bulky knits or cotton sweatshirts, thermal base layers of silk or synthetic fibers, wool socks, knit cap, scarf, gloves.

With your having posted on the Germany forum I’ll bet your doing a Munich/Salzburg/Vienna departure for the Christmas Markets??

I’d wear your coat and boots on the plane. I’d take a base layer and a down or fleece vest. I’d put your warm hat, gloves, scarf or neck gaiter in your personal item so you have them.

With just 8 days I’d take 2 pr pants, 3 LS Tees and a layering item such as a drifit quarter-zip. This would include the items you wear in transit. Don’t take a bulky sweater. You’ll do better to go with things that pack better. Cashmere works too.

If you don’t live where it’s cold enough for you to have base layers, I like the brands Lands End and HotTotties. I like the LE Heat Crew which I size up and wear as a regular shirt all winter.

If this is the right tour you are not changing hotels too often but you do spend one night in Hallstatt?? I’d just leave my suitcase on the bus and take minimal stuff in for that night. Otherwise most of the hotels are somewhat accessible from the bus( don’t have a long walk pulling luggage from where the bus has to park).

You can take as much luggage as you can carry.

Sure you can live for 8 days out of a carry-on. It is easy.
Wear one pair of jeans and pack a 2nd pair. Take 8 long sleeve blouses, 1 sweater, long johns like cuddle duds, 2-3 long sleeve turtle neck t-shirt., a light night gown. 4 pair socks, 4 undies. Roll everything. Wear a messenger bag that can carry a few items too. Wear your coat, scarf, hat, gloves, and boots on the plane.

I wouldn't freak out about that "just carry ons" thing. As most comments have made clear, you just need to be sure you can handle your luggage yourself during the tour.

Just to clarify in case this hasn't stood out in this discussion:

There is literally traveling "carry on only," meaning you don't check a bag so that you're hauling all your stuff with you at all times.

And, there is traveling with (roughly) a carry on sized bag + another smaller bag, but checking the suitcase for your flights, and only carrying the smaller bag onto the plane with you.

There is no right or wrong choice, it's a matter of doing what works best for you.

Many people on this forum do check a bag, including me. I usually travel with a 22" bag with wheels, and I usually check it. TBH it's because I want to bring (a) more toiletries than I can fit in the dreaded TSA quart sized ziplock, (b) some cutlery to use in my hotel room so I can "dine in," (c) a travel camera tripod, and/or (d) hiking poles. I've traveled with a 22" roller + a shoulder bag + a small duffel that resembles the Rick Steves Euro bag, several times. Including a two-week vacation when I traveled extensively by rail around Great Britain. I managed all of it easily.

There are pros and cons to each approach. These days, especially outside the US, air carriers have shrunk the acceptable size/weight of carry-on bags. I'd rather not sweat whether my carefully packed 21" or 22" bag will fail the size/weight test of some random gate agent or counter agent. I pack my "must have" and valuable stuff in my actual carry-on, plus a change of clothing, and check the other bag. That's worked for me.

I think you can get a lot more in a 22" bag than you'd expect. Plan to take advantage of layering your clothes, figure out how to wash some socks and undies in your hotel room, plan to splurge a few Euros on a laundry service for other clothing items if necessary, look into packing cubes, test pack like a madwoman - and have fun!

When you are travelling in cold weather you will constantly be wearing your coat, hat, gloves and boots and it almost doesn't matter what's underneath. Two different hats and scarves will add some needed variety. Make sure your base layers will drip dry overnight and you will be fine.

Thanks to everyone who commented. I think I can do it ! I'll just have to cut back on my hair products and wear a hat a lot LOL.

The 8 kg weight limit for carryons on some carriers is really used up fast if the carryon itself weighs 7 lbs.(3.5 kg) And if you haven't experienced it yet, yes some airlines do weigh the carryon.

Decant the appropriate amount of each toiletry into a suitable small bottle. Don't cart around pounds of that stuff when you will need mere ounces for your short trip. I use solid conditioner rather than liquid to save weight because my trips are long; I wouldn't bother doing that on a short trip, because I'd have to saw a small chunk off the bar of solid conditioner.

We have been on trips for up to a month with carry on and a small backpack each. Every trip you get better at it. I found Sarah Murdoch's video on packing light very helpful. You can do it Judy! Have a great trip!