suggestions for packing on the 13 day Scotland trip in Sept.

On our first trip in 72 we took standard large suitcases -- never again. And we haven't. Basically we wear one and pack two outfits. And then add three or four different shirts or top to mix and match to get a number of different looks -- then a light weight rain/wind jacket, and five changes of underwear plus three pairs of socks and that is about it. Elsewhere on this site, Steves' has a packing list. It is good and will fit a carryon. Good luck

I remember Inverness had a great service laundry. I took my laundry before dinner one night & it was ready after lunch next day. I never pack for more than a week no matter how long I will be gone and I do some hand washing, mostly underthings, & try to find a laundry every 7-10 days. You will really regret having a large bag and having to drag it along. Probably no one will say anything if you do have a larger bag, but you will probably wish you had a smaller one by the end of the trip.

I just got back from Scotland and was there for a little over 3 weeks during May. You might want to review my packing report that I posted - https://community.ricksteves.com/travel-forum/packing/my-scotland-packing-report - but in a netshell, I wore the following clothing:

4 tops (2 LS knit tops, 1 merino wool sweater, and 1 lightweight sweater)
3 prs pants (1 fleece-lined pr. of charcoal grey leggings, 1 pr. Eileen Fisher black ponte knit ankle pants, and 1 pr of Jockey grey knit joggers)
5 prs of undies (side story there in report)
5-6 prs of socks
3 soft bras
1 lightweight nightgown
1 Calvin Klein water resistant rain jacket with light fleece lining
1 Orvis sweater/fleece vest that I wore on days that were too warm for the jacket but too cool for just the top).
2 prs shoes - 1 pr of Oboz walking shoes (used for hiking and long walking) and a pair of Hey Dude canvas deck shoes (wore evenings and for light walking)

The freedom I felt from having a lighter weight bag more than compensated for having to do laundry in the hotel rooms. And laundry really doesn't take much time at all. I just used the hotel soap or shampoo, then roll them up in towels to compress and remove moisture, then I laid them out to dry. Many hotels had heated towel racks and heaters that were good for dryer, but otherwise, I just laid them out on the bed or hung them someplace.

Just to say, we took 2 biggish bags on our 3 week UK trip in 2019. We did NOT regret it. It wasn't a problem and we were public transport only. That said we are taking 2 slightly smaller bags on our 4 week British Isles trip in September. Striving for packing lighter is something we want to do. However, we did fine with the bigger bags in 2019. For reference, we were 64 years old in 2019.

I travel to London in November.

Have stayed a month. Female

2 lightweight Lands End Fleece ( pullover and zip up)
Ex Officio rain coat with hood
2 turtle neck tops
1 long sleeve lightweight sweater that hangs mid thigh
2 pair of leggings
1 pair of gloria Vanderbuilt skinny black jeans
Lightweight sweats with pockets for PJ bottoms
Long sleeve tee for PJ top
1 capeline midweight crew
3 pairs of underwear
2 sports bras
1 Amazon black puffer vest with 2 outside pockets and 2 interior pockets where you can secure your phone and mini ibook
1 scarf
1 knit beanie
Wear Keen Kaci slip ons on the flight and pack Keen
Targhee lace ups. Costly, durable and comfotable. The targhee lace up are nearly 10 years old. You’d never know.

Travel with carry on and small under the seat back pack.

There may be a difference between packing a carry-on size bag to carry on the plane vs packing a carry-on size bag to check. I have the original RS 22" rolling carry-on, which is now too large to carry on for many airlines, so I check it.

But it is soft on the front, and I put a lot of stuff in the front pockets. It may also weigh more packed than current airline maximum carry-on weights, but I find it easy to handle once I'm on the ground, on public transportation, on stairs, etc. I have no problem traveling with it for two weeks - you would be amazed how much it holds but also how little you really need to get by on. Just plan on doing laundry a couple of times.

And if you need rain gear for Scotland, just wear it when boarding the plane, then use as a cushion or blanket - thus less to pack. Then as Claudia suggests, have a smaller backpack to carry on, which you can put overhead if you've checked your primary bag.