Don't have a solution for you but I will say fleece is plain warm! I have fleece sheets on my bed (not flannel) and at night I turn my heat down to 55. In a 55 degree house, it gets hot in there and I have to throw the fleece back sometimes. And I don't have a lot of other things on the bed - just a thin bedspread (no quilt because my dog sleeps up there) and a thin blanket for her to lay on to keep the spread from getting too dingy - it's a lot easier too to wash the blanket vs spread
Also, the spreads aren't really made to wash often. Anyway, how about backing it with fleece? I've done that and the people I've given them too love them.