Also check out Open Range, especially the Journeyer models. If you are able to handle a 5'er, check out the DRV coaches. They have 3.5" walls, so more insulation than the normal 2" on others.
As far as cold weather, we've been living in our Foretravel MH for a year now in SW Missouri and central Oklahoma. We have 50A service, so we run a couple of electric heaters for most of the heat. Remember that 50A service is two 50A legs, for a total of 12,000W, while 30A service is one 30A leg for 3600W.
Since you will be staying in one place for 2-3 months at a time, a towable is a better choice than a MH. As was pointed out above, you won't be able to drive as far or as fast with a coach in tow as you can in just a car, so keep that in mind.
Many campgrounds offer a weekly or monthly rate that is considerably cheaper than the daily rate. You may or may not save money using a coach vs renting someplace, but you may find campgrounds to be easier to find than a 2-3 month lease on an apartment.
David Lininger, kb0zke
Heartland mpg 181 (sold)
1993 Foretravel U300 (for sale)