Mark & Vicki (& Scout) -
We have several Mountaineer owners here, but a quick forum search didn't find any posts specific to the 375FLF.
All of the current Mountaineer floorplans are listed as *New*... a whole new line-up, although a few (including
the 375FLF) were added at the end of last year. Hopefully some of the Mountaineer owners will chime-in soon.
As for *Winter Camping* - there are "numerous" threads about that topic, and the general consensus is that most
RV's (regardless of how it's labeled/marketed), will need additional protection against extreme weather/COLD.
Most folks use skirting and/or some other type of insulating method to protect the water lines, pipes, etc.
Higher insulation factors [walls, floor, roof] are of some benefit, but the marketing "labels" (industry-wide) are
somewhat mis-leading.
Here's some previous threads - not specific to Mountaineer, but should be helpful.
http://www.keystonerv.org/forums/showthread.php?t=10892
http://www.keystonerv.org/forums/showthread.php?t=15501
http://www.keystonerv.org/forums/showthread.php?t=14525
http://www.keystonerv.org/forums/showthread.php?t=15061
http://www.keystonerv.org/forums/showthread.php?t=14661
http://www.keystonerv.org/forums/showthread.php?t=13308
http://www.keystonerv.org/forums/showthread.php?t=14672
http://www.keystonerv.org/forums/showthread.php?t=14061
PS, I deleted your other post only because we ask that members not start 2 identical threads in different areas of the forum.
Good luck with your decision,
Terri, the Chevy co-pilot