Ed, I just didn't know if Bluegrass knew that the mattress doesn't cover the slide gaps. I didn't think about the bare area left by replacing the king mattress could be a problem, but now realize that it could get cold without the mattress there, as the mattress has to provide some insulation. I am not sure what is under the mattress area.....is that just plywood, or is it the sandwiched foam board?? I know in my previous pop-up, it was just bare plywood.
I see you are from Alaska.....no wonder you use that foam. The missus doesn't want to camp when it gets below 30 or so.
Chap