I've got some solar back-up power for running sump pumps during flooding, if the power fails.
I think the system could run my oil burner, but not for very long. (Old batteries).
My main backup for the house is a 5KW gasoline generator.
With fuel on hand, and intermittent running, maybe we could keep
the house warmed up for about a week.
It would be longer, if I wasn't wasting so much gas on the snowblower..
But, if the local stations had power, I could buy more gas as needed.. Maybe.
A few people up in NH had to use generators for a whole month..
Serious ice storm in the NE that winter..