your suggestion implies that the system is built rationally and to a standard. Who's to say something in that config file isnt used as a hardcoded setting somewhere in the code?
You might be able to spoof the DNS to the TV without changing anything on the TV. However, it's quite possible that the code inside the TV is sufficiently insane that what I suggested would not be possible, even if you spoofed DNS externally; that's why I was wondering if anyone had tried experimenting.