I'm in North Dakota and want to know the difference between using number one diesel

From your post that I quoted I wondered if a noob might see that and think its OK to run untreated #2 at that temp and think he'll be OK.
I couldn't tell you how many trucks I've seen up north shut off and use an apu overnight at -15 then have a service call with the heaters in the morning.

Its not way up north for a fast weather change several years ago I was humping groceries in OKC with a 2 wheeler at night in a T shirt and sweating my a z z off, 100 miles or so later when I got back to Tulsa there was freezing rain...about a 50 degree temp drop, crazy stuff.

 

one thing that sould prevent this problem is changing fuel filter regularly, or draining water out of filter from the drain on the bottom, when fuel tanks run really low the sloshing effect with pick up the water from condensation so it is important if you have hot days and cooler nights to drain fuel filter at least once a week or so. Unless you get a bad batch of fuel from the pumps, the refineries have such large tanks they tend to sweat in the summr and if they don't wactch moisture it goes right thru, seen it before and heard of certain stations having water in their fuel.