Inverters are easily installed whether by factory, dealer, or by yourself. They are not exclusive to high-end units whatsoever and they are readily available at Walmart and BestBuy to name a few. Our TH had a factory option for an inverter but I didn't want to pay 500% more for something I could easily install in a half hour. Need at least a couple of batteries for a few hours of TV viewing daily, adding solar will help reduce genny runtime for recharging.
It's true that it is difficult for large rigs to access some of the national parks as well a some of the older state parks, and very few allow riding from park to off road vehicle trails. There is plenty of good info online detailing off road trails with many in NM and surrounding states. Enjoy your new TH!!!