gkreutzer, I guess I'm confused. We have the queen sized costco topper on our bed at home and it would be a bear to fold it up to fit under the jack knife sofa. I've moved it a few times when DW gets into house cleaning frenzy and folded twice to 1/4 area its still difficult to move. Seems a CA king even more so. I think I'll try getting our topper under the sofa in the 211 and if I can make it fit that's the way to go. ( all I need is 72" and the queen is 80 x 60) Do you roll it up like a sleeping bag and tie it? Do you need help when you get it out from under the sofa?
markopolo, I've used regular foam before and even 80" long twins should fit folded between the backs of the seat and the sofa/dinette. Unfortunately, memory foam is habit forming ( makes any mattress feel like a million $) and if I can make it work thats what the DW wants.