And now I post with character and plot stuff!
Replying to myself to give some more info now that I've had some time to think:
Brand ___ (PB Sebastian Stan): A New Yorker who comes from a kind of strict Catholic family. His younger sibling (open to any gender!) was one of The Academics, both the baby and star of the family. Brand's not much of an intellectual himself, but he's open-minded and enthusiastic and was close to his sibling despite their parents' tendencies to pit them against each other. Brand's about 35-years-old so there was a bit of an age gap between him and the sibling.
Looking for the sibling for sure, also open to the parents! Also also would love to have a significant other take the trip with him, possibly with their relationship being on the rocks due to, y'know, grief and all that stuff? Could be someone he's been with for a long time, or another surviving family member he met and started dating in the aftermath of all this tragedy.