> Generator 5kw - you want something with a higher duty cycle than you need so it can run for extended periods

Note that fossil fuel can age out, even with stabilizer.

There are dual- and tri-fuel generators out there that can use natural/methane gas and/or propane. Consider propane as you can get pretty big bottles and it does not expire so can sit around for long periods of time.

Yeah gas / propane might make the most sense. I already have a big 3026L propane tank.