What if "To live you must die" is meant to be far more literal, albeit subtle, than most have at first suspected. He literally must die, completely and totally, to beat the DO at TG. He will then be able "to live" when he is next reborn/spun out by the wheel. If he loses (i.e. doesn't die), there will be no more rebirth b/c the Wheel will be broken by the DO.