Since the return of Dak Prescott, the Dallas Cowboys have become a potent offense, scoring 33.8 points per game, the most of any team in that span. The defense is only allowing 17.0 points this season (tops in the league entering the weekend). If you do the math, that means the new Dak offense is averaging almost twice as many points as the defense has averaged all year. That kind of difference will win you a lot of games.
Against the New York Giants on Thanksgiving, the offense started off slow missing out on opportunities to get points when they crossed into Giants' territory.