Tonguez
A suffusion of yellow
I don't think that there are any societies, where more than four generations live together. They tend to be tribal. I doubt that it could go much further than that, in practical terms, without creating a small family village of sorts. In that case you still wouldn't really be dealing with many more people, due to stratification and separation within the village.
until quite recently most people didn't survive past four generations (great grand parents) so the point was largely moot, in my culture (which is tribal) great grandparents were recognized ceremonially as the link in extended families but beyond that they weren't present to keep the bond going for further generations. Up to 6 generations is what we would consider a clan/subtribe which occupy a particular locality and share rights but are not considered 'family' and beyond that is the Tribe/Nation.
My grandmother got to 6 generations when she died in 2001 so that was interesting in as much as we still had a common extended family bond. But since she died even that has faded.