[wingnut60]

No matter what the brochure/salesman says--if you expect to be at the same comfort level at 0d as at 45-60d, it is your mistake. Cold is the absence of heat--if you leave any type of enclosure without heat, the inside temp will eventually come to match the outside temp. If you don't want that to happen, you have to provide a heat source that can counter the outside temps sucking the inside temps down. Even then, placement of water lines near the outside walls is always a problem.
I lived in WY for 10 years--coming from TX, I found all this out the hard way, and it wasn't in a fiver, either.
As to the rest of the warranty issues, you are becoming aware of the industry lack of standards/customer service...not necessarily only a Montana domain. Buy a $150k DRV and see if it will stand up to 0d with no heat source--there is a reason that you see 100-250gal propane tanks next to fivers/TTs in cold climes, along with skirts/hay bales around the perimeter.
Joe