I'm currently gaming once or twice a week.
Taking my time that I can't (realisticly) do anything about is college and a two-night-a-week job at the library.
Taking my time that I
could free up, but choose not to, is:
My love of reading books (I have entire WALLS in my house COVERED in books... 95% of them read, the ones that aren't only because I keep going back and re-reading a few favorites over and over again... and I'm ALWAYS buying a bag of books at the used bookstore, or a new one now and then.) Reading is an obsession with me. Not just fiction either... numerous mythology (Ok, that's fiction, but... you know what I mean), history, cultural, art, etc books also make up my collection. RPG books too, of course
My love of anime is just about as encompassing as my love of books. Anime... manga (Maybe that should go in books, I dunno)... etc.
If I dropped those two, I would probably be gaming every night a week. But I can't enjoy ANYTHING that much. I'd get burned out inside of a month. And burnout is not a good thing.
My "limit" for gaming would probably be three nights a week, and only if I DMed one of those.
As for how a S/O can effect it... Well... I've been lucky. My GF is sorta like a female clone of me. Except alot more attractive

. Thus, two of our hobbies can be shared anyhow... as for reading, well... thats "private time" stuff. The gamers I know with S/Os around here GENERALY don't have to cut back on gaming as a result... and a lot of people have been led into gaming because of that, in my area. I don't think that's quite as true everywhere, though.
Should you cut back? If you even START to get the "ho hum... might as well game, nothing better to do" attitude, YES. Burnout hurts, and can last YEARS, if you recover at all. Otherwise? Game on, man.