i saw this a few months back, i never even considered doing something similar for a cold frame!
I've been on the hunt for glass for a diy cold frame but now i know what to do.
and i've got one of those cheap plastic greenhouses (the pokey ones from QD) which i brought a replacement cover for the other day, reckon you could use an old cover (or a new one if you wanted) to line the inside with to stop the wind, obviously wouldnt work for the full scale greenhouse though.