Typically--they have a tent parked on the edge of Parisian Courtyard before you go into the tunnel in-between Mels + Theater Cafe! It's been like that for as long as the event has had Parisian as a house venue, but due to the tighter logistics, they have the courtyard be a mixture of outdoor scenic setpieces (like the bridge with the dead kids in La Llorona/Monstruos), that is then overtaken by the venue enclosing the roofing with a mesh.
Before they made some major changes to how the venue worked, they actually used the former FFL Audition rooms for the sake of the finale sequence of the likes of Halloween 2015. But I think due to TM logistics, they've been forced to discard using that space as the minion costumes are parked inside the room.