Russ, you can do very well with much less than 150 pounds- consider that a reasonable backpack load for a weekend will weigh in the neighborhood of 45 pounds or so...

I checked out my trunk and the contents were:

sleeping bag - absolutely essential IMHO - should be rated to 20F

day pack - w/FAK, 10 essentials bag, water, and snacks. A

tool kit - jumper cables, socket set, shovels (two) folding saw (two),
pick, hatchet

small plastic crate w/ folding esbit stove, cook set, esbit fuel, alcohol stove and fuel

large FAK

coveralls and exposure suit

Elsewhere in the vehicle I had a small knife and flashlights.

I would estimate that all of the above weighed about twenty-five pounds or less. I only had about a gallon water all told - which is a bit on the thin side and i could stock more food.

Forget freeze-dried. I prefer well wrapped snacks like Clif bars and canned items, nuts, and similar. FD is for backpacking where water is available.

I could easily stay in or near my vehicle with its contents for a night or two, and I roam around in sunny SoCal. If I head for higher, colder, and wetter places I would probably add a bit more.

My vehicle, a small sedan, is a genuine solar cooker in the passenger compartment. It is usually parked in full sunshine. The trunk, by comparison, is surprisingly cool. I am not worried about long term storage of food and water there.