LVR1000 your question is will it gel in the UP after sitting for awhile and what can prevent it. I have been around diesel engines for work and pleasure for over 20 years in northern MN and the answer is yes it probably will unless you take some simple precautions.
Stay away from buying Bio diesel. The anti gel stuff doesn’t work that great with it. When you get close to your destination and the forecast is for cold weather, fill it up with straight number one. You’ll get bad fuel mileage and less power, but if your mix is no less than 75% number one and 25% number 2 it should not gel at 20-30 below. That will work better then any gas, or anti gel additives you can buy. If you’re still worried, install an after market fuel line heater and fuel filter warmer. Also always carry an extra fuel filter.
To make sure they start, run synthetic motor oil. If you are at a place that you can’t plug in, take along a little charcoal to heat up the oil pan, of course be careful doing this, but that has worked for me more then once getting them started when you’re in the middle of nowhere. Good batteries are also a must. Use starting fluid as a last resort, it is real hard on the newer diesels.