A second thanks to zephyr17, I appreciate the restroom tips. Do people usually trek to the shower in shorts and a t-shirt or something? I assume there's room to change there. I'll bring some throwaway hotel slippers to use for that purpose I guess. Is the shower hard to get into in the morning? Do people wait in line, or ??

On second thought, I think I'll use a small third bag that I can put inside the big bag and take out when I board, that'll probably be the easiest way to do things.

Thanks to serpens for the route guide suggestion, I will definitely do that. The scenery is a big part of the motivation for making the trip by train.