I met a guy who built a really nice place off the grid. I will qualify this by saying I am not sure this was all to code.
Power - he had a large number of deep cycle batteries running to an inverter. This powered led lights, TV, etc . He had a couple solar panels that were really just meant to keep the batteries charged (no load) while he was gone. He had a diesel generator that ran the fridge, charged the batteries and ran the well pump. This was usually on for a few hours a day.
Water - a couple large drums in the attic that would be filled when the generator was on that provided gravity flow to the sinks, toilet, shower, etc. used a small on demand propane water heater supplied by 100# tanks.
Waste water - the sinks, shower and urinal ran into a "grey water" field. The toilet had a large, buried tank that would be pumped out once a year.
Heat was via wood stove an a small propane wall furnace to help keep the temp up during the winter while he was out and about