I do this with my vehicles on the Oregon coast with the ever present threat of earthquake/tsunami.
Long and short in pistol caliber magnum. Smith m66 and Rossi 92 in .357 and 50-100 rounds in the car. Smith m629 and Rossi 92 in .44 magnum in the truck. Both vehicles have 1 large camp knife (8 inch Bowie or Bolo) and a 4 inch Bravo1. I pack an axe, a one man cross cut saw, and shovel in the back too, plus a week’s worth of food, camp cookware, and water filter/bottles. Sleeping bag, tarp, and cordage.
The big snows we just had knocked out power for a week and closed highways for several days. A good rehearsal for the big one.