It depends on what station one holds in the pecking order. Elders, pioneers and ministerial servants are often found outside their territory boundaries. Generally these are asked to "jump over to Macedonia" if a neighboring congregation is in greater need.
The rank and file are generally strongly encouraged to stay where they are assigned. If someone chooses to disobey and go to a congregation other than their assigned one, then that person is considered rebellious because theocratic order is put aside. Often priviledges such as carrying mikes, prayer etc. are withheld.