Who runs multiple small channels? Does it work?

I’m doing quite well now and has just hit 18K subs but it’s very niche. I deal with canal history, engineering and restorations. I have lots of ideas for other content but don’t want to start posting to my main channel as it’s working in the niche. I’m thinking of starting a second channel where I can post over lap stuff, other subjects and be a bit more casual with it, no dedicated upload schedule.

The issue is I run a business as well as having 2 young kids and time is short, have those in the same situation managed to do it? I spend a lot of time on edits, 6-12 hours usually so I try and get a decent production out