maybe something like this: http://www.asus.com/Multimedia/Wireless_Kit/WAVI/

i think it could be painfull to use big picture if the tv is too much far from the computer.
from my own experience with big Picture, i use it withth dual screen capacities of my grpahic card
And for some games, there is a sub menu that popup after the launch of the game from big picture screen , it require the mouse device to be completely launched.
So let me know one detail , if you can't have a look on the tv in the secondary room how would you be able to click at the right postion of the screen from the other room ?
this issue is recurrent to dual screen method, and the one proposed by Abe , in the previous topic.
Also its a expensive device, and don't forget you have to export the sounds flux too with dual screen method.

//red

well my system is powerfull enougth to convert a film, have 30 odd ie windows open, a ftp transfer in progress and run a game with the 2nd monitor by default still in windows without a problem the only catch i see is i dont have a device that would function along the lines of a hub like the asus one above that is cost effective and would run off a wired network connection since the device above by asus is expensive and no idea if it will work, and even if it did with the home i live in the signal could be broken often this leaves me with basically getting a 2nd computer just for the tv which in one hand is like hmm okay dokey, on the other hand, omg the money on electricity