Not a lot actually, since it's all just text (and my assumption is that most will be smaller data for likes/follows). Probably a few hundred megabytes at most.
that’s a fair assumption pfps/banners might take up some more space though, unless he’s using an external host for those too
Those aren't in the database, they're in a separate folder
oh, wait how do you know all this
Jeffalo's talked about this stuff on Discord