Well, I'm going to north dakota. When I worked in Wyoming for a couple years, I saw temps with windchill in the negative 60's. My Duramax gelled up driving down the road a couple times. My rig I am building for the trip is a 427 gasser, sure to fire up at whatever temp. I would like to have the same in a welder. The simpler, the better.
Coldest I have seen was where the Alcan begins at the border. -72 degrees. That's life or death right there, and I'll go with my gasser on a day like that.