According to the Winter Bash 2017 FAQ, users can opt-out of the Winter Bash by clicking "I hate hats" in the snowflake menu.
I hate hats! How do I get rid of them?
When you click the snow flake icon in the top bar, a popup appears that has a link labeled "I hate hats!" This will turn off all hat-related events on all sites for you. You won't see people wearing hats, you won't be alerted when you earn a hat, and you won't be seen wearing a hat by any other users.
The FAQ doesn't specify what happens if a user has a change of hard and wants to re-opt in to the Winter Bash.
- Can a user decide to re-opt in to the Winter Bash after declaring their hatred for hats?
- What will happen to the hats they've earned before opting out?
- What happens if a user meets the requirements for a hat while opted out?