I usually set up a completely separate partition on a different drive for Timeshift. That way it doesn’t gradually eat away at system space on the main drive. And even if it was on there, it would have already eaten all that space in readiness, so to speak.

Also, I don’t have it backing up my home directory. I do that separately.

But that said, this post has given me the reminder to see if there are any old snapshots that could do with deleting. And there were a few. It’s now back down to roughly the same size as my main OS install again, which is about as big as it needs to be if you think about it.