John, you did just fine on the reply.
Does yours have two hoses close together hanging below the rig? Actually, there's a third that is the freshwater tank drain. Those two hoses are the low point drains. On some 2006 models and later (but not all 2006, I think) the low point drain valves are inside the basement storage area. The hoses hang out below but the valve is inside. If yours are inside, then skip this part. If yours are hanging below and have caps on them to drain the water lines, that's the first point that will freeze. I had to heat tape ours and then wrap with insulation followed by duct tape.
The water tanks and water lines are in the belly. There is a furnace duct to keep that area from freezing. It works quite well but only if the furnace runs enough. And it will eat a lot of propane. If the furnace quits running, it will freeze. I would think 45 would work so long as you are not in it and dealing with that temperature. I hope you will have a large propane bottle because with temperatures in the teens and below and the furnace on 45 you'll get maybe 3 or 4 days, 5 or 6 at the most, out of a 30 lb bottle. The 45 setting might give you a little more time on one bottle. You can get a larger external bottle to connect to.
Re-reading your post, I guess the Montana will be in Boise where it doesn't get quite so cold? I just checked Boise's average and last year's temperatures and it is surprisingly mild for winter. Looks like they had some low in the upper teens but not much colder than that. If that's what you expect, you'll probably be fine with the furnace on 45. If you have those older style low point drains, though, ours used to freeze at around 22 degrees F. If yours are inside, no problem.
I've kind of rambled. I hope this helps somewhat. Keep in mind if you get three or four hours below 27 degrees without the furnace running, it will freeze. So it's a good idea to let it get down to that 45 degrees before it gets that cold and then let the furnace maintain it. When you visit the rig you may want to turn the thermostat back down before the temperatures drop below freezing. Just a suggestion.
We have a number of people here who have survived winter in a Montana. Maybe some of them will jump in and help.
See another Montana or Mountaineer on the road? Flash lights twice, it might be one of us!
Steve Reigle (pronounced Regal)
Fulltiming since 3/21/03
'03 3295RK
'05 Ford F250 SD Lariat CC SB 6.0L PSD/TS FX4 4x4
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