We have developed and "easy/breezy" way to set up, sleep and make up our trailer bed. Perhaps it will work for you too.
Look at posting #4 for my explanation and photos.
If your bed is wide enough you might want to make up your bed the German/Austrian way. Simply cover the bottom mattress with a sheet. Each person has one comforter which is covered with a duvet. No top sheet is involved. When the bed is "made" you fold the comforter in thirds and place on top. You simply wash the duvet and bottom sheet. Another benefit is you don't fight over who is hogging the bedding :-). See photo of my hotel bed in Innsbruck, Austria.
Perhaps if your bottom sheet is a flat sheet you can simply tuck in the sides that butt up to the wall. Rather than using your fingers to do this you could use a sturdy board such as a plastic breadboard with a handle EcoSmart Poly-Flax Red 12-inch L x 16-inch W Cutting Board - BedBathandBeyond.com
or one like this PreserveŽ BPA Free Plastic Cutting Board - BedBathandBeyond.com
. The sheet would then be easier to take out with a firm pull.
If your mattress is standard with a channel of piping on the top you could use a sheet gripper Sheet Grippers (Set of 4) - BedBathandBeyond.com
. You could secure the sheet by clipping it onto the top
of the mattress next to the wall. You might also want to use this sheet hugger Sheet Huggers (Set of 4) - BedBathandBeyond.com
It can be fun to think of creative solutions to our trailer challenges. Good luck!