Hi Gary,
Welcome to the Heartland Owners Forum. It's a great place to get information and help, and reflects the feeling of family that Heartland Owners have for one another.
Have you been to the
Heartland RV Website? The entire Heartland Product Line is represented there. You can download brochures, and you'll also find important resources such as construction info that describes what's "under the covers."
"Breaking the bank" is a relative term of course, so you may get answers from Heartland owners that reflect a variety of models.
We have a Landmark, which is a high-end unit, suitable for full-time use. It's "comfort-tested" to zero degrees, and we've used it on extended ski trips with temps down to 30 below zero (F) and have been comfortable. We've also been in places like Moab, UT in the summer, with temps at 108. We have dual pane windows, which help, and also opted for the 2nd A/C unit in the bedroom to help cool the unit. We also opted for the fireplace for winter use. We've used tips from this forum to help with both cold and hot conditions.
The Bighorn and Big Country lines have lower price points, but share most of the construction techniques and materials that the Landmark uses.
The Elkridge has an even lower price point. We have friends who use theirs in the heat of Texas and in the cold of Breckenridge, CO in the winter.
Anyway, if you visit the Heartland site, you'll see the full range and can get an idea of how the different product lines might suit your purpose.
And of course, other owners will no doubt chime in with their thoughts.