I Went to the North Pole Once is a great prompt game for the holidays!  I played with my kid (4yo) and had a really fun time coming up with ideas together (many of his ideas revolved around nutcrackers and hot cocoa)!

I've got a full review here too on the TTRPGkids site:

www.ttrpgkids.com/2022/12/19/review-of-i-went-to-the-north-pole-once-a-tabletop-rpg-about-creating-a-holiday-adventure/