If it’s in the minus twenties, I let it idle for five to ten minutes. Minus thirties and forties, I do a full ten minute auto start cycle, and then hop in the truck during the next ten minute cycle. When I get to where I am going, and she has warmed up, before I leave I auto start and drive within that ten minute cycle. Minus fifties, it’s two full cycles and then crawl on those square tires to wherever you are going and then leave it running until you get back home. Battery blanket, oil heater and full synthetic oil. Down to minus thirties, I have the plug on a timer but colder than that, I leave it plugged in wherever I am. Burn most of my fuel in the driveway.