I think you should be fine.
We did CRT in October, and I recall taking some pictures of the mosaics on our way out to see the fireworks because there were very few guests there. The pictures were taken around 8:32 pm, and I believe the fireworks started at 9:00 pm.
The CMs there let us know exactly by what time we needed to leave. If I remember correctly, they said we needed to leave by 8:45 pm that night.