We just returned from our first trip to Europe and a RS tour. We were gone for 22 days and each did a 22" bag (4 backpack convertible bags, and one with wheels for our youngest). We hated the wheeled bag on all of the stairs and on and off of transportation (on the boat, RER, Metro, and train during our independent travel time). It was heavier then the backpacks because of the frame and wheels - making it tougher to maneuver. There were a few larger bags on our tour - but most people had much less then us and I was envious. I never noticed what people were wearing or if they were repeating outfits.
I have just finished unpacking and doing our laundry and realized that we way overpacked. I would have NEVER believed it when setting out - I thought I was down to a bare minimum. Our bags were heavy - almost 20 lbs. and if we were doing it again we would pack less. They didn't seem heavy before leaving and we were amazed at what we were able to pack in the 22" packs. By the end they felt like a ton and repacking at each destination was a chore since they were packed so full. I did some sink laundry but with packing cubes we were able to get in lots and lots of clothes - too heavy. My youngest had 18 different outfits, the rest of us each had 15 tops and 7 bottoms and underwear/socks for 14 days. Then we had umbrellas, rain shells, swimsuits, we each had one nice going out outfit, pj's, we each brought a towel (although 3 were smaller yoga towels and 2 were thin beach towels), toiletries, an overstuffed medicine kit (that we did not touch - thankfully), youngest had a blanket as well. We had a small laundry kit (liquid tide packets, sink drain stopper, clothes line) and each child took 2 plastic hangers - one shirt, one pants hanger (helpful for socks). We had activity things (coloring books, books, nook, cell phones), paperwork (for our tour and travel books) and journals as well - all adding weight and taking up space. Then there were the chargers (phones, cameras, e-reader, etc...) and the adapters and plugs (we did not need 6 adapters - the rooms never had that many plugs - 2 would have been plenty). It all added up. We had a hotel in Austria that had very reasonable rates to do laundry for us so we did have them do 2 loads for us at that point. It was really a luxury instead of a necessity since I could have continued with the sink washing - but that allowed us to wash everything up to that point and with my overpacking we were good for the remaining 14 days. We packed an extra bag that we planned on using for purchases but after using up consumables, throwing away some items, and unzipping our bags and using the expandable space we came home with the same bags we went with - except that we checked them on the way home instead of carry-on only.
Just as a packing reminder - The weather is unpredictable in Europe and while we were expecting colder weather in Switzerland we really packed for warm/hot weather (tank tops, sundresses, etc...) for the entire rest of the trip. We arrived in Rome to 80 degree days (not the 90+ we were expecting) and we had 70's-80's for the entire trip - with the exception of our time in Paris, which was in the 50's-60's. It ended up being cold and overcast (off and on rain as well) in Paris for several days and we were wearing our one pair of long pants and one set of layers (long sleeve t-shirts, performance zippies, rain shells) for several days. Perfect touring weather and we were so thankful to avoid the heat - but my girls were not wearing their sundresses and sleeveless tops. We left from Belgium and a heat wave was just beginning as we left - but our temps never went about 84 degrees while there. If the weather had been different I imagine we would have needed the clothes that we packed (after dripping in sweat, you need to change for the evening and re-wearing items becomes much harder).
