The best that I can suggest is to insulate the garage door. You can order a kit like this:

http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

Or you can do it yourself for a little cheaper by buying a couple of sheets of polystyrene insulation, sheet metal screws and some washers. Cut it to fit each section of the door and screw each piece on. A cordless screwdriver or drill will be your friend.
Depending on how big your garage is, you will probably need 1-2 space heaters to keep it warm. I would definitely not move the snakes out there until you have everything up and running and stabilized....