OP, Gvanbrunt's idea is a good one: find out what's taking up all the ever increasing amounts of space and that will be a clue on how to address the issue. It may be something you can easily fix.
...data isn't usually huge, unless you have temporary TV recordings or other stuff living in there.
It depends on what you mean by huge. FWIW, I routinely have multiple gigs of data (between 2 and 6) floating around in my MC Roaming directories and it's not due to TV recording.
I didn't really use TV in MC 18 or 19 (didn't even have a tuner until late in the MC 19 lifecycle), but had multiple gigs (5 or 6) in those directories on my main HTPC when I deleted them. The big offenders usually seem to be library thumbnails (which are important) and cached web content like theater view background pictures (which are less important).
My MC 20 roaming directory right now is about 2.5 gigs, and about half that (over a gig) is just cached theater view background pictures. As far as I know there's no way to limit that kind of caching from within MC. I just go in and "clean up" in explorer once in a while when it gets too big.