This is an interesting concept and should be easy enough to emulate in Tyvek. I had already tried to shape a groundcloth so the sides stood up like this, but without pegs or other supports it was less than perfect. Using some elastic cord to make it conform to the shape of one’s sleeping mat is a good idea. The SOL material used here maybe would provide some extra insulation but it would not stand up to many uses I suspect. I sometimes use a space blanket as an emergency ultralight ground cloth myself. The older thicker ‘Space Blanket’ might work better, but I suspect the insulation advantage is over-rated compared to the weight/cost and that Tyvek will provide a more serviceable alternative: http://www.instructables.com/id/Semi-Bivy-Keep-your-sleeping-bag-dry-and-warmer/
