I've read through a lot of the threads on doubling up quilts and bags for winter. I was thinking of giving this a try this winter in the Socal Mountains. I figured it would be a good experiment because often times it will only get down to around 10-15 degrees. I'm thinking of combining a SD Nitro 15 degree bag along with a Te-Wa 25 degree quilt. With appropriate clothing, do you think I could get close to 0 in this setup? The quilt has 14 oz of down in it. Also, it seems to me it would work best if I draped the quilt flat over the bag. Does that sound right, or would it work better to form the foot box and slide the bag in that way?