That is one advantage of living in an RV -- but let's face it, there plenty of downsides... storage space for one, strong shelter for another. And how do you heat your home in a grid down scenario?
Also, do you have land (acreage) to park it on, or do you just rent from someone? Issues like security, sewage, water supply, etc. could be a problem.
An RV can be heated by a wood stove or those made from candles and clay pots. The main thing is to be very careful! When I lived in far north eastern New York State, lots of people had homemade wood stoves in trailer homes. You must make certain the smoke and gases vent sufficiently far away from the structure so as not to set it on fire, and there must be intake of fresh air to prevent CO2 poisoning. Every spring, the snow would melt to reveal the burnt out shells of trailers go up in flames, and every winter, some people would fail to show up when expected, only to be found dead in their beds. The same can happen in more substantial structures, but it’s less likely. In 1978, one of my history professors didn’t come to work or answer his phone. His ex-wife found him and their two children deceased of a CO2 leak in their bungalow. The dampers were sealed by soot and creosote and the place was sealed up with insulation. But the majority of people heated with wood and did just fine.
As for flushing toilets, you don’t need one. Use an outhouse. Water can be gotten from a spring, a river, (just boil it before ingesting), or a dug well in some locales. Handy men have built windmills to pump water. A rain catching system can lead to a basement cistern. Want to live really off-grid? Get hooked up with Swartzentruber or Nebraska Amish. I lived with the former, and within about three months, the adjustments became just normal to me, not a novelty.