De googling in a complex family

I have a complex multi household poly family with kids, so the “spousal” acceptance factor is a high bar to clear. I would like to start de googling, but I know that there is no way I’m going to convince everyone to do it all at once.

The biggest sticking point is gCal. We all have shared calendars with varying levels of privacy settings for the adults, and a shared kids calendar for doctors appointments, school events, etc. I know, we are every stereotype about poly people and google calendar.

Is there a thing that will let me move to another calendar system, that will still let me share my calendar with specific google using people, view and edit the shared kids calendar, and handle event invites, etc from everyone else? Assuming that only I move to it at first.