Ohhh....I like the idea of doing a throw blanket first. That would help me iron out any problems with the construction (no pun intended) and also help him see if that's "warm enough" or not. (Or maybe TOO warm!)
Personally I think he's a little crazy, but he does get really cold at night even if the room feels warm (to me). We usually end up with all the blankets on his side of the bed. Maybe I'll just make it twin sized and it can just stay on HIS side of the bed. I'm a pretty warm sleeper and usually have to stick my feet out from under the blankets to stay cool enough to sleep comfortably.
Hmm...there's an interesting thought. King size quilt, but done in "halves" - one half "cool" for me; one half extra thick and heavy for Mister Icy Feet.
Oh, I'm going to make myself crazy with this. Thanks for all the ideas, ladies!