I like to think of JR's death-by-18-wheeler in the '90s reunion movie as having happened in Season 15 (per non-existent DVD count --- or Season 14 by what
@Barbara Fan likes to call "original count") which never happened anyway.
That year (1991-1992), I want to learn that JR thinks he's Digger Barnes' biological son around the same time Bobby & Ray discover Pam may be deceased of adult-onset neurofibromatosis -- making her Digger's daughter after all (Rebecca had mistaken -- or lied about -- Pam's paternal sire).
So Pam and JR may be half-siblings, driving him nuts. Until it can all be undone DALLAS-style and DNA testing proves JR is Jock's child once and for all. (Did JR pay the DNA clinic? We'll never know).
I envision most of the men (and some of the women) going down in a derrick platform collapse on doomed Section 40 in Spring 1992, the last scene of the original series. So perhaps some of them survived.
And JR wound up in a nursing home because he was..............
80 years old!