[themodelplumber]

First, just to offer that it's pretty lucky to have even this much family connection going on, that's really great.

Second I think that multiple-model is pretty awesome. Groups can organically figure out what works best in different contexts. WhatsApp here, a conference call there, some long planning emails over here.

Finally I'd mention that 25 might be a very flexible call limit depending on the framework. You can do pretty huge calls if you plan out and communicate the needed structure in advance. For example, moderated participation, planning to do sharing in rounds, taking time to monitor chats, etc. It can really help people to plan their participation in a way that's comfortable and sustainable.

Just some thoughts coming from a pretty big couple of extended families, good luck.