I'm doing this now (minus OTA because I can't get any signals). My 622 is in the bedroom. I ran a 75' HDMI cable to my 32" LCD in the family room thus always making it TV1.
In the bedroom, I have the component cable connected to a 26" LCD. I also have the composite video connected to this TV from TV2. Anytime I want to watch different programming, I switch the 622 into dual mode and select the composite input on the 26" LCD. It doesn't look too bad, but then again I don't do this very often.
I also have a UHF Pro 6.3 remote configured to run TV1 so I'm not hauling the TV2 remote back and forth. This setup works well for me.