With enough preparation of both inside and outside of motorhome, this can be accomplished.
The only thing both you and your occupant need to remember is that this is not a permanant structure, so don't expect things that just are not going to happen.
There are people living in trailers in Alaska, google them, read what they've done to prepare their 'homes' for LOTS rougher winters than you'll have in CO.
As far as heating is concerned, I would only consider having the motorhome propane units as backup only. You'll be much better off having energy efficient electric units.
Check the motorhome for location of plumbing. If all water pipes are inside, not really too much to worry about freezing, unless you have power outage and lose all sources of heat. Of course, with 12V power, and a full propane tank, you'll have enough to keep tenant warm for up to 12 to 24 hours.
Don't let anyone say this can not be done, because it's done in much colder climes. You're only downfall will be in not having proper preparation.
HOW TO: RV in the Winter - YouTube
The above link will probably have more information than you'll ever get from most with only opinions. Go on YouTube.com, there's lots more videos similar to this one with varying advice and suggestions on how to make your RV 'winter-living-ready'!
Good Luck, Derek