I have had my Explorer deluxe and and poncho down below zero a number of times this fall.. no worries really.
http://i7.photobucket.com/albums/y26...IMGP0033-1.jpg
We - (my son and I) - slip a space blanket in the middle between layers - we both also sleep in - 25 down sleeping bags. Im considering sewing them up - with a layer of insulation in the middle - I'm just not sure what to use yet.
http://i7.photobucket.com/albums/y26...IMGP0031-1.jpg