it is easy to say that BYU football games are a much better experience. Attendance is very low at Stanford. Like feels empty some games kind of attendance. Student turnout is much greater at BYU. Let's not get started on Stanford's band...
But back to your point, unless Stanford has a magical season next year, I would expect this game to be one of the more highly attended on Stanford's schedule because of BYU fans. I would also expect BYU fans to outdo Stanford fans at this game as well in terms of crowd noise.