If so, how long can they stay there?
They are long gone. The Livestock Show and Rodeo is in there right now.
I actually don’t think the Livestock Show is in there, I think it is mostly in the Reliant Arena, the Astroarena, and Reliant Stadium (and the carnival in the parking lot). (Basically all around the Astrodome but not in the Astrodome).
The evacuees left the Astrodome in September. Mostly moved into motels and hotels and apartments. They left motels and hotels for apartments sometime early this year.