Air Suspension in Cold Weather

[linneje]

I have never had this problem before this year, but in December I took a trip in -35ºC weather, and after sitting outside for a couple hours the air suspension had completely deflated. When started, it reinflated and was fine. No problems until today, a couple months later. Exact same problem about -35ºC today, and after sitting a couple hours I find the air suspension deflated completely. I bring it back home and put it in the garage (not heated, but insulated and much warmer than outside) and it stays up.

I suspect the check valve is freezing up due to condensation in the extreme weather. Anyone else had this happen with the air suspension in extreme cold temperatures?