I have been using the G96 Gun Treatment for years with good results.
The factory says it is good down to -50 degrees.

http://www.mcssl.com/store/c0e84d9548e54592a9555a19c32338/gun-treatment-and-gun-oil/gun-treatment

Nifty-250

"If you don't know where you're going, you may wind up somewhere else".
Yogi Berra