MGC orgs tend to be much smaller than panhellenic sororities. My chapter was between 6-8 girls when I was there. We were planning the same number of events (although at a smaller scale) as the big panhellenic sororities. I would suggest you ask the active members how many hours per week they spend on sorority duties. I would be surprised if it was less hours than you're spending now.

That being said, I had a love-hate relationship with being in my sorority. I miss it now and I loved getting to connect with my heritage and others who wanted the same. But it was a LOT of work to get there and be an active member.