Exactly. Around here, many people are putting in whole house generators that run on propane, and come on automatically. I still use one that give me 25 amps. Enough to give me water, run my fridge, and the furnace if it's winter. Just not all at once!!!! I have propane for cooking and hot water, so I can actually take a hot shower when all around me is otherwise chaos.
If I were planning for future catastrophes, it's very simple to build a water system that consists of a group of pressure tanks that are full of water. You can charge them with an air compressor that draws almost no amperage when an emergency strikes.
But I don't have any real worries about the end of days. We get snow and high winds. Freezing rain often kills the power, but my area tends to get power back quickly. I often have to bring my generators to friends' houses to give them the bare necessities as they have no power for days on end.
Just did a job for an engineer who showed me a great idea. He welded a nipple to the exhaust on his generator and hooked a heat proof 1 1/2" line to said nipple. He runs the line into his stove pipe and can run the generator inside the garage, where nobody can steal it. Great idea. He didn't do it for fear of theft. It keeps the generator dry in adverse conditions.