Hi, well after that pic there was a twanging noise and my hastily rigged system slipped under my bum down to my legs, which were toasty. Slipped out of bed, retied and it was good. Two weeks ago I did another sub zero camp -2.3'c. Similar sort of problems with it slipping about. I was in a 2-3 season sleeping bag and only my legs were a bit cold. If I'd had a more sensible sleeping bag it'd probably have been much warmer!
Saw some designs for a fabric suspension system which I'm going to sketch up and give to the wife to make.