What a lot of you guys don't understand is the rent schedule of housing (if you can find any) in Western ND or Eastern MT or WYO. The oil boom has pushed rental pricing to the sky and people are on waiting lists.
Forum member RonR was in Watford City in the Winter. His electric was included with lot rent so he rigged up heat lamps under the trailer and had some skirting built for the purpose. One of his mid-Winter problems was the weed growth under the trailer, lol. Locals know how to insulate and make things work. RonR has an Arctic Fox with the Winter package.
If you had more time. you could do what I did and build out a trailer for the purpose. The rebuild is in the thread in my signature line, "The Cowboy/Hilton". For your immediate situation, I'd buy a trailer that has a 4 season package and take it from there. If you're lucky enough to get located to Watford City or close, there is a heated indoor park there. $1000 for a heated garage and not having to worry about the cold is worth the price. I believe the owners were going to build more of these units in different locations but I don't keep up with Bakken gossip too much since oil went down in price.
Good luck with your future trailer. The Forum is a great resource and there are a lot of discussions about cold weather living and full time trailering. Hope to see you around.