Purely talking about the show, since TV Sansa seems to be all about the Stark dynasty, I'd expect her to eventually marry some sperm donor to pop out a few heirs and otherwise ignore the guy as much as possible. When talking about Bran getting the throne, his inability to produce heirs was a concern to her.
Tyrion, who knows? There's a bunch of other minor Lannisters out there, presumably, if need be.
As far as main character endgames, I'll categorically state that I think D&D completely rewrote the Cersei/Jaime stuff apart from them both dying at the end.
The endings for the remaining six original POVs, I expect the broad strokes are accurate, albeit with elaborations or some alterations.
Bran being king is locked in, to me, because D&D quite obviously never cared at all about Bran as a character and there's no way they would have come up with that ending by themselves.
The Six Kingdoms/North split, as presented in the show, is total nonsense. I don't know if that's a show-only elaboration, and, say, in the books it will be Sansa as Lady with Bran as King, or if GRRM has some surely more detailed and elaborate method of arriving at the same result. I briefly wondered the writers wanted the "Queen in the North" stuff as a shield against Dany going full-villain along with Cersei, but on reflection they've never shown the degree of awareness to warrant such a pre-emptive action; so probably not.