As I understand the system, it's not a matter of keeping the TV "part" on or off. At the origin, the system attempts to connect to the satellite system. If it does, you have access to TV until you're out of range. If it cannot connect to the satellite system, you're out of luck unless the system is reset (although "resetting" the system is being quasi-debated in another thread).

Of course, it would be awesome if CO and LiveTV could devise an update so that some sort of "reset" could be done once a flight is within range of the satellite system. ^ (I was told on a recent YYC-IAH flight that if the FA were to "reset" the system, everyone would have to swipe their credit cards a second time. Don't know if that's true or not.)

tv_man?