In our guest room, we have two extra-long twin beds. When put together, they are the same size as a king mattress. I made two matching (scrappy) XL twin bedspreads. When the beds are separated, they look great. When the beds are pushed together, I simply overlap the quilts in the middle. Until you get up close, you don't even notice that it's not one quilt. Bet this would work with two quilts with different batting weights, too!