Hi Kim,
My experience is with a Landmark which has a bit better insulation underneath. I'd guess the roof/floor/sidewall R values are similar.
Keeping the temp inside the coach comfortable isn't too hard. We're in the Colorado mountains right now with the furnace set to 70 and the fireplace running when we're in the living room. If it gets really cold, below -10F, I may fire up a ceramic disc heater in the kitchen to supplement when we get up. The furnace keeps the bedroom plenty warm and along with an electric blanket, that's plenty.
If you don't have the Yeti option (holding tank heating pads), you need to have heating pads installed. While they they have the underbelly open doing that install, I'd also have the fresh water and kitchen water lines fixed up with heat tape and insulation.
The main difficulty in extreme cold weather is with the water systems. Even with the Yeti package, if temps get to -20F or below, you'll need to take additional protective measures. We've been down to -30F a few times.
We have an owner-written
Water Systems Winter Usage Guide that details what you need to do to keep water running.
If you have slideout awnings, you'll need to support them so they're not damaged by snowfall. And you'll need to clean the snow off before it gets too heavy.
I'd also suggest a couple of extra fittings for your sewer.
A clear adapter and a twist-on gate valve will let you visually confirm that the black tank is completely flushed out. Then when you close the black tank valve, also close the twist-on gate valve and let it sit for an hour to make sure you don't have any leaks. If you have a little leak, you can easily end up with the whole sewer system frozen solid from the ground back up to the tank. Once you're sure it's not leaking, you can open the external gate valve.
You'll probably want 2 or 3 ceramic disc heaters like
this Pelonis unit.
