Just back from a quick 2 night trip to a local campground, our 13QBB overwintered well and all systems were great. Earlier this spring I added 2' x 2' interlocking rubber floor tiles from Lowes and it was a great add on for very little money. The tiles provide nice cushion and temperature control. The nighttime temps were 40ish and last year we would have been wearing shoes all the time in the camper, now socks only are fine. I highly recommend doing this.
Mitch