Hello,
Many US military personal who serve on an isolated duty station, in effect live off grid. For example I was in the U.S. Coast Guard and stationed at Cape Sarichef, Alaska for a year. [It is at the end of Unimak Island.]
We had three large Caterpillar generators. We got our water from a reservoir that was filled from mountain runoff. I would go the reservoir when needed and start a small hand pull pump (during the winter could take almost 30 minutes to get started.) This would pump the water along a buried pipe line, with evenly spaced vents (to let the air out).
We had a fuel farm. Our heating was via two #2 diesel fueled boilers. All heating equipment and almost all the vehicles ran on diesel fuel. We got our water pressure from a 5,000 gallon water tank on a hill above the station.
There was a septic tank and dispersal field. Which seemed to work just fine in the bitterly cold winter, which surprised me. We got most of our supplies via a Coast Guard C-130 once a month. We had a runway constructed of volcanic ash and stone. There was also a World War II runway about a two-hour drive away.
If we were to have gotten stuck there with no re-supply we would have been in trouble for heat once the diesel ran out. There are no trees on that island. We had an incinerator and a dump for anything that could not be burned.
The only way on or off the island was by air plane or helicopter. Other than having some way to provide heat in the winter that would be the perfect place to live. There were caribou, moose, whistle pigs [groundhogs], red foxes, seals, and a pack of feral Alaskan huskies. There were brown bears there, too.