[......] anyone "on the grid" who claims to know is fooling themselves.
Nonsense! You obviously haven't heard of "the rest of the world" and assume that everywhere's like where you are. There are vast areas of the world that don't have national or state grids (but do have a power distribution network - i.e., are "on the grid").
I live in Darwin, in Australia's Northern Territory. The NT is big - 1.4 million square kilometres - but only has a population of about 200,000 people. There is no territory grid, so Darwin's power supply isn't connected to anywhere else. We're powered by natural gas.
Afghanistan hasn't got a national grid either. When i lived in Kabul a few years back, that city's power came from diesel generators most of the year, plus a bit of hydro when the snow's melting.