I agree with zephyr7 as to the restrooms. Use downstairs ones. They get much less use both because there are three vs one upstairs and because most people are upstairs and don't want to go downstairs. We didn't mind. It's the only exercise you'll get on the train other than exercising your moth muscles at meals and your jaw at the jaw-dropping scenery.
I disagree with zephyr7 as to the medium size suitcase. You have a number of options:
- Sleep in upper berth then lots of room to keep suitcase on seat of unsetup lower bed (seats). Disadvantage is headroom up there. Advantage is ability to move around more in room while getting ready for sleep and in morning. Don't bop your head. Very low headroom. Check it before you tell SCA which bunk to make up.
- Pull down upper berth. Throw bag on it. Then push it up. My bag always fit. Is bag soft sided? If so, take out your morning clothes, lay them on upper bunk after pulling it down along with your toiletry kit and the stuff you take out of pockets. Your bag will be that much thinner.
You do not define "medium" Airplane carry-on? Bigger? I haul up one that used to meet airline regs but no longer does as they've shrunk them. I'll be 75 this month and I'm short and stout.
Here's another thought which we also did on last long trip when our big bag was BIG (airplane "check only" size). Pack a small soft bag with just enough to take up the stairs what you need. Put it in the bigger bag to haul around. When you get to the train, take it out. Leave the big one downstairs and carry up the small. Shortly before arrival, bring small bag downstairs and stuff it back in the big one and leave it there. Carry off one bag. That worked great because we had one BIG, one medium mentioned earlier and the soft-sided one. That worked great for us because we only dragged two around but the third meant we could leave the big ones in the rental car trunk while on trip, bringing in the other into the hotel for one-night stays. On the trains between two check-bagged stations, we checked the BIG one, left medium downstairs for emergencies and carried up the little.
Bring ziploc bag to store keys, watch, earrings, cell phone, small items so you have them close by while sleeping. Keeps them together (unless you'd rather keep them in purse).
You could bring along gaffer's tape and tape extra pillow from lower bunk to ceiling above your head if you sleep "upstairs". Makes sudden sitting up less painful.