Depends how much time or money you want to invest but...You could get a large sheet(s) of 1" styrofoam (4' X 8'), cut to size needed, then cut in half. Glue a piece of 1/4 or 3/8 plywood/osb on each half of foam...hit the bottom side with someThompsons or the like. Attach hinges to plywood to enable folding in half for easier carry and transport. Get some scrap carpeting and glue to other side of foam halves. I did this when I had a hub style shanty and it worked great.