Hey Backhoe!
Those cats won't be denied, lol! I know about the water heater and toilet tank as sources of emercency water sources. My biggest worry is if the vehicles are disabled, and there is a forced evacuation. How do you pack it all out? If I was settled permanently, mind you we're in the desert, so no 8 ft of polluted water to worry about(plus we have the wrench to immediately shut off the gas), why should we evacuate if we have ample supplies? Heck, the Mojave river is just down the road, and so is the CA aqueduct.
That's a good question- I guess if I had a choice, I'd get and keep an old Army Duece & a half 5 ton truck as a bugout vehicle. My brother-in-law actually has a neighbor who keeps one in his carport. The downside being license, insurance, keeping it in running condition-- they aren't something you take for a spin to the grocery, normally.
When we had the wrecker and welding services, the wrecker and service truck were handy to have, as they could carry a fair amount of cargo. Alas, the service truck got sold, and the wrecker needs a new master cylinder- to say nothing of a current license plate and insurance- to make it roadworthy & legal. I still use it as a boom truck around my MIL's old store, but stopping 8,000+ pounds of truck with the hand brake is a little hair-raising...