At the 2nd annual Florida Hang, it got down to 28. I was in thermals and sweatpants and sweatshirt with hat and 2 pair socks. I was on top of walmart blue pad and fleece blanket. I had my walmart summer, 50 degree bag I think, around my hammy and ridgeline for most of my coverage. My jacket on the head side. I was warm except for my feet sometimes that kept going past the pad. And yes, the bag did keep the warmth around my topside probably due to no wind.
I believe that setup worked due to no compression what so ever ala peapod.