I have a similar setup (but 16kw) and similar risk characteristics. I do have a backup to my backup. For heat, a Mr Heater with a few days worth of propane. For at least some power, I have an EcoFlow Delta Pro with a solar panel (50 ft cables so I can keep it inside but have the panel move around a bit outside if needed.) I also have a smaller EcoFlow River for portability that uses the same panel – I store it in a faraday bag. It doesn’t completely backup the whole house generator, but it’s something and it’s portable and doesn’t rely on a utility company being operational. I’m planning to add more portable solar panels as my next step.