Are You Going to Run Into the Gilligans Island Problem?

The show was such a ratings hit that it became clear to me instantly that all conversations about ending the show would be over. That's when a b c said, oh, we were thinking more like ten seasons. And so the compromise ended up being six. But i personally wish that we could have done it in four. Even just hearing you talk about wanting to do four, having to do six, but pulling them back from ten? How hard would that conversation even be if you were making a show like lost?