[Festus2]

CONGRATUALTIONS ON YOUR "NEW" PURCHASE and welcome to the forum. From your post, I am assuming that you will be using it as a hunting cabin on the weekends and taking it home and plugging it in during the week (???). Not sure about the temps in that area but I would think it would dip below freezing at that altitude and time of year.
Since you wont have any hookups, you might want to consider the following:
1) Take a portable heater with you - powered by your 4K generator. I often use "Mr. Buddy" - a portable propane heater that has a low oxygen cut off on it. It is safe for indoor use provided you crank open a window or have fresh air coming into the RV. Another option to consider in lieu of or in addition to a portable heater.
2) The Polar or Arctic Package is essentially a marketing gimmick leaving you with the impression that it will be of great use in continuous cold weather. It is not. You must have your furnace running in order for the water lines to receive any warm air. The enclosed underbelly wont offer you any effective protection against the cold. There are too many openings and gaps allowing cold air to easily penetrate the underbelly and large air space and your water lines. Don't be misled by this Arctic or Polar designation. If you can, you might consider covering as much of any exposed water lines as you can with foam pipe tubing.

If you do a Google search, you will find lots of information about books that are devoted to RV maintenance and repair. Some members will probably have some specific suggestions for you to consider.

Enjoy.