If you go the liner route, I would suggest making a trial run at your house first. I am just clausterphobic enough that when I added a liner to the inside of my bag, I couldn't stand the closeness. So what do I do for snow camping? I take an extra down sleeping bag (unzipped all the way) and use it as a comforter OVER my regular bag. Of course, you gotta have the room in your backpack and be willing to carry the extra weight but most snow hikes that I have been on are pretty short. With my Troop, we just basically have the boys hike over the hill from the parking lot and call it good. (One time, the Leader had the boys start at the parking lot, hike over and around the hill and then back to camp next to the parking lot. He thought it was great fun (the other adults weren't laughing))