I have the lightweight wally world bag at a pound and a half and I see people saying the temp rating is more like 45-50 degrees then the suggested 32 degrees on the bag. I should note that I also take a warm winter hat with me on every trip even in summer as well as wool socks and that alone seems to help add a few degrees to my bags. I'm thinking that the kylmit inertia xl sleeping pad used with the wally world bag would help to improve its temp rating by a few degrees as well. I always have a dry sweater that I bring with me as well. The socks and hat add very little weight and I usually end up wearing the sweater for a few hours on cool evenings before bed. So I don't consider the sweater as extra bedding weight.

I should also add that the coldest trip I've been on to date was in the 20's F at night.