I have had good results hanging my deer with skin on for 21 days in a 30-40 degree garage. You just have to be sure the temp never rises over 40.
And you don't want it to freeze either. I find that by hanging with skin on, I don't get that hard shell that needs to be trimmed away.

This is why I prefer late hunts in Eastern WA, and I always haul my deer to the relative's in Spokane.