Change the fuel filter, and pour some of the Power Service, 911, Howe's Lubricant in the filter. I know, breaking the rules, but it needs to run. Pour a bunch of additive in the tank. Be patient, and then try and start it. If you need to put a torpedo heater near the front of the truck, put cardboard along the sides of the truck to hold the heat in and let it heat the underside of the truck.
If all this fails, hook a chain to it and drag it somewhere warm. Then add some #1 fuel to the tank and try starting it after a few hours. -25*F is cold!!! I would definatly make sure the fuel is blended or even run straight #1 in those temps.
Michael