in case anyone else stumbles on this thread...
The sensor bar distance to the console is irrelevant because all it does is transmit an IR light. This is why the wireless bars work, because all they do is create an IR source. (there was a video a while back of someone using two candles instead of a sensor bar)
The wiimote has an IR camera that picks up this light and communicates it via bluetooth to the console. The only distance factor is the BT radio to console.