How would your sim live, like what would you put in the house and help fill their needs? Example; Cooking Lights Entertainment Etc... I know the waterfall and swimming in the beach fills hyg...
In my game I have a cc canning station (probably MTS). It would make the off-the-grid sim busy with food related activities. Canned stuff can be eaten, but I don't know for sure if that specific cc stove requires electricity. If so, you could always make a canning corner on a community lot, and go there like a daily chore to fix your meals. Those canned jars can also be sold, either from inventory or at the market table.