Rivers of Light Arrival Time with a Fastpass

If I get a Fastpass for Rivers of Light, how early do I need to arrive to be seated? I don’t care if I get a good seat, just if I make it in the theater. I am going on a day when the projected crowd level is 4.

I was wondering the same. We have 8 in our party so I bet we would need to get there early to get seating together. Bumping to try for an answer for you!