It’s possible this year we’ll get the winter finale in Episode 8 on December 12, if The CW sticks with that schedule.
Last year’s winter finale was Episode 7, airing December 13.
(Legacies is meant to have a big Christmas episode this year, but it’s not actually set on Christmas, which is intriguing.)
We don’t have a date on that yet, but it shouldn’t be too long after Episode 6 — since Episode 5 airs November 15, Episode 6 should be November 21, November 28 is Thanksgiving so I’m sure they’ll be taking a break, and I imagine Episode 7 will air on December 5.