I'm no help at all. I sleep on buses, I sleep on planes, I sleep on car trips (when I'm not driving) plus I get nauseous when I try to read when riding.
And I take either a blanket or cape with me when traveling, buses and planes always have it too cold for my comfort zone. And I don't like the idea of using previously used, possibly unwashed between customers blankets on planes.
You might suggest to the group that if they want, they could bring along a lap quilt for comfort. Also maybe a small cooler. I usually did, and used it as a foot rest, since my legs swell when they are flat on the floor for many hours. Plus, most bus foot rests are a joke...or at least were on the Via buses I used to ride on tours.