Ah, my mileage was people put “No” or “Maybe” unless they were 1000% sure they could come, meaning there would've been a date to pin once every 3 months or so.
Nah, in my opinion: Make them regular (like once every two weeks) and run a session as long as the GM and at least 3 players can come.
Simple as.
I guess our mileage is that most of us have a no for something they can't or won't reschedule, a maybe for something they can reschedule, and a yes for empty evenings. And most of us have enough empty evenings that we can reliably agree upon a date a few weeks in advance.
With a previous group, we had a similar rule, though we only had three players, so that's something.