something that works well in Scandinavia (or at least in Norway), that perhaps should be implemented by TD owners: NO TOP SHEET. You use a fitted bottom sheet, and the comforter has an easily removed cover, for cleaning. After each trip, you remove the comforter cover for cleaning. This avoids the problem of having to keep that top sheet tucked in.
On some scandinavian beds, each person has his/her own comforter, so two comforters sit side-by-side on the made bed.
Make sense?
-Al