It just depends, some Toy Haulers, usually the nicer ones sometimes have an inverter for the TV system, but you need to verify this. These are sometimes part of a factory installed package. A dealer, or you, can install one as long as you know how to and use heavy gauge wiring and ideally keep it close to the batteries. That's the next thing you need to address is a good bank of batteries.
Depending on the National Park you may have some troubles with the near 40' Toy Haulers. It's not always the length of the site itself, but the turn around and space to actually back into a site. Pick some of your favorite site and see if they will accommodate the larger Toy Hauler. Older ones are the ones least likely.
You are going to be limited to where you camp and ride if you are trying to stay in any National Park or most State/USFS/COE sites unless they specifically state they allow off road ATV/MX bikes. That said places like the Paiute trail have great places to camp, you're probably likely to find some places in NM to camp and ride.