Its stupid and unfair to lower townhall , really this is your christmas event? You didn't even consider how will affect lower townhall who stay and strive on their bracket.
The lower bracket for event items is a broken mechanic for anyone smart even to understand they can put far less effort into getting items than they would need to in a higher bracket. I stopped growing as quickly as I should when I realised that it got harder for quests and events because if the brackets...
As your realm matures and grows more buckets will be added which will future incentivize you to upgrade your TH. This was the last bucket change (used for standard solo events), Not quite sure what the snow fort buckets are, I’ll try and find out for you. But I, and most others agree they need more work and balancing.
I recommend stopping at 12 till you can get at least 15million night and all upgrades and research and lots of troops etc. I purposely am not upgrading my town hall for as long as possible and it’s allowing me to get 3 star rewards and leaderboard prizes for most events. Once you hit 13 you go into the next tier and it's much harder to get those rewards. Focus on might always, never levels.