I just moved to a more rural location and I'm seeing that electricity supply is much less relaible than I was used to. I'm looking at diesel gennies. I prefer having a fuel system I can deal with, including filling it myself by portable jugs if really necessary.
At about 20kW, I can run the heat pump, well pump, water heater, some lights, furnace blower, fridge, freezer, and more. That 20kW genny will burn approximately 1/2 gallon per hour at 50% load.
So 500 gallons of diesel gives you a long run time:
500gal less a 10% safety margin = 450 gal
450 gal/0.5 gal/h = 900 h
900h/24h/day = 37 days
And if you can get by with running the genny only 18h out of every 24 (should be easy!), you're looking at 50 days on a tank full of fuel. That's plenty for even the worst credible emergency situation.