I made a search and found 7 RV Parks in or around Williston, ND. In my opinion if your going to be there awhile you might want to think about buying a vacant lot and pouring a concrete slab for your Newell and setting up 50 AMP service. Might be cheaper depending on rental prices/land values etc if its a long term/permanent job. 40 below your a brave soul
I thought 45 was cold and told the wife to start packing cause Sugar land here we come!.
Sean