Can my humble, single-user instance handle it?
Maybe?
FWIW this information is based on the experience when using remote hosting not self hosting.
The main issue for us was tuning the database performance. The bot can beat your database to death sometimes and just throwing resources at it won't necessarily solve it. related low effort meme Our experience was that the bot performance hit wasn't really noticable immediately but it adds up as more and more communities are added to the database. There also seem to be bursts of database load at times, maybe that's when new instances join the network? They seem to only last a short time though and haven't really caused problems.
TLDR- Expect an eventual performance hit. If it's too much you can always disable the bot or adjust what it does.