While our temps don't get to -30 Wind chill; it's not uncommon to hit the high 20s for lows. I never leave my rifle(ML or otherwise) in a warm area overnight. It stays in a case inside my truck until I head for the blind and then it goes in the truck bed unless its raining. You don't have to worry about condensation in the gun or on the scope. I just finished a 5 day hunt in S. Texas where it was 24 degrees 3 mornings. I use BH 209 and didn't fire a shot or reload for 3 days and it ignited on the 4th day when I killed a nice sized feral hog.