I've always heard its about 45 degrees, you could maybe afford to go over that a bit if its only an hour or two a day. I don't let a deer hang any longer than one night, even in very cold temps, until I get it in a locker. I like to eat venison and don't want to risk the chance of ruining anything I harvest. It's not worth the risk, and I think that's the ethical thing to do.
Walk the night, travel light, cross the Rio Grande
Someone strums a mandolin, soft gulf breezes blow
My new life is waiting in old Mexico
-Robert Earl Keen