I'm probably more of a Christmas person than a Halloween person, but I generally don't really like the holiday season (Halloween-Thanksgiving-Christmas), and am not too huge on decorating even though I like the aesthetic of Christmas decorations. Since my sister is the one who usually makes us decorate, and she's probably not gonna be here for Christmas, we're likely not gonna decorate this year at all outside of a wreath on the door.
Which means, my dear pet Norfolk Pine will get to be our Christmas tree, and I am a proud parent.
As far as how soon is too soon... I don't really care tbh. After Halloween, I'm okay to start mentally getting into some sort of Christmas mindset (I enjoy wishing people a Merry Christmas the day after Halloween for laughs), but the start of Advent is usually when my family finds it acceptable to start decorating if we actually decorate.