Matt
Iris wore a simple outfit for her spanking job - gotta keep it from interfering with the swing! And marketed it as a way to keep at least one part of you warm in the snowy weather! When not taking her turn(s), she'd probably hang with the Chocobros because she adores them, or pestered Cloud and Talcott, or bothered the Lux crew.
Kratos would be there, maybe with Freya, we'll seeeeeee. Otherwise he's largely just staying out of the way and watching for any Vallo-Bullshit to happen.
Brigitte would like to drag Syd out and see everything at the event, because it's no secret she loves this time of year. Mead Sampling tiiiime! And snowballs at Syd, sorry. She'd donate like $5k to the Sanctuary <3
Hawkins team??? Must revisit.
Steve would really soak it in, and offer help anywhere he can. Otherwise he'll enjoy the hot cocoa and donate toys