For really cold weather, or possibly in response to your particular situation, may I suggest the Cabelas MT050 one piece insulated coverall. The heat retention properties of this particular outfit are outstanding. I plan on packing it in along with my boot blankets for a long sit this Saturday. Temps are only supposed to reach the mid 30's with an overnight low around 20. I typically wear a thin pair of odor eliminating undies with either a turtlneck or sweatshirt and uninsulated pants on top for the walk in and then would put the one piece outfit on when I get on stand.