You can stockpile diesel for a generator (unlike electrons). That's what actual prepping looks like.
Take it from a Ukrainian.
Much easier to just buy some solar panels to recharge the electric truck.
And if the needle is so far towards apocalypse, then the horse beats your diesel. Repairs itself, refuels itself, and replaces itself.
Take it from a Ukrainian.
PS: my dual-fuel gasoline/LPG Renault Twingo in Poland will outrun any Cybertruck on the continent.
And, unlike electricity, you can stockpile gasoline.
Source: I've mucked up multiple small engines with bad stored gas.
Propane, sure, but now you're talking about something fairly exotic, at least in terms of vehicles you can buy "off the shelf."
In any case, you can't produce propane yourself. You can "produce" electrons with a solar panel.
Edit: My bias is toward North America, but I know of only one model of "normal person car" (city buses don't count) produced in the last 50 years that you could just walk into a dealership and purchase new: The Honda Civic NX. And that was sold for only a few years and only available in California.