If you like the work of Denis Villeneuve and Chris Nolan like me I would really recommend Arrival, Inception, Interstellar and Tenet if you haven't seem them yet.
Without spoiling anything Arrival in particular is just mindblowing amazing IMO.
If you're in a mood for a monty-python-esque dystopia: Brazil (1985) is somewhat sci-fi-ish, as seen from the 20. Century. And it is “Christmas-themed“.