A 1980s style pickup with the bodywork replaced with aluminum or fiberglass would probably last forever. I've known many 80s Ford or Toyoras to be very fixable after the original engines quit. Ususually, at least in the north-east, the snow and salt rots out vehicles bef0re they really get to junk level
Or a '90s 4-banger Nissan Hardbody with a manual transmission. My father has one and there's a list of people waiting to buy it off him if he's ever willing to sell. Those things are great.
