Did you ever try to turn the receiver back after letting it cool when it went into protect mode?
You have a huge room which is up to 4500cu/ft. You are asking a lot of that receiver and I am not surprised you were able to shut it down. BTW if you are listening at reference level in that massive room, you won't have any headroom for dynamic peaks in Blu-ray movie soundstracks and are at risking of not only shutting down the receiver but also potentially clipping your speakers. Superbowl audio is not even demanding content.
