I agree with CanoeStream suggestions.
1.Water is gonna be ur main issues.
2.Heat, depending on ur location and source, can be trying.
3. Since ur at the looking stage, consider some of the later models that have heated assist for the holding tank.
This is usually in the form of a heat pad under the tank. Most, I believe, are 12v
powered. Of course, if you're hooked up to 120VAC it should still function properly.
4. One thing I fought in the winter was moisture on the inside windows. I would wipe those down every day and, keep wetness out of the unit. For example, if you make a pot of coffee in the morning..Get rid of the coffee grounds quickly after it's finis perking..
5. When living in a trailer of any kind full-time, you're gonna run up against all kinds of unique issues that demand creativity and, adjustments to your old habits. Don't tell me ur a "pack rat"..lol
I agree with CanoeStream excellent assessment again abt towing in the winter time in high altitude. But, if you do..be sure to wash it down often~