Yoshida mentions in a new interview that FF16 has enough content to fill four drama seasons, which is on brand with the Game of Thrones seasons that the staff watched. Here's an excerpt of what he said:
Yoshida: "I was and still am a fan of Final Fantasy series, even if I'm now part of the development side. [What is memorable] is always the story, which pulls at your emotions, making you laugh, cry, etc.
I would say that FF16 has enough content that can cover four [overseas] drama seasons. The game has virtually no loading times, is top-notch, and our goal was to make a story where once you pick it up you can't put it down. But of course, we'd be worried if you didn't sleep and pull all nighters while playing the game, so uh, yeah...
For us though, we really put a lot of effort into the story to make it one that everyone can enjoy, so we really hope you can look forward to it!"