In Alaska there are many generators in use. As many 'off-the road-' homes there are, that is not surprising, of course.

My first summer up here I worked at a wilderness lodge,. We had two diesel generators, a large one and a smaller. We usually used only one with the other for backup. We ran the generator an hour and a half in a 24-hour period.   That provided juice for topping up two freezers that had huge chunks of iceberg in them that we gathered weekly from a glacier -front lake, lights (Of course summer days in Alaska don't require much artificial light) , but not for cooking (we had a kerosene cookstove) or hot water (instead of a water heater we had an on-demand hot water system).

I just realized that that experience doesn't help in your parents' situation. For one thing, there was no alternate electrical system in place.

Good luck, Janie. It's never easy, is it. What solution(s) do your parents fancy?