I know you guys aren't used to it.....but damn that's still shirt and flannel weather. Drop it another 40°
LOL I'm kidding. You can put a tarp over the car or truck to keep the wind down. Just don't run the motor and die of asphyxiation

Also if you have to lay on snow an old table cloth (with the plastic on one side and the fuzz on the other) works pretty damn well from a blocking out some of the cold and most of the wet. I have a big piece of neoprene material about 5'x4'x.25" that was a game changer. But I always kept a old table cloth like that somewhere stuffed away on the jeep.