I honestly think that the Warblers throwing the competition is the only way ND will win. Because at this point, ND doesn't deserve to win. They waited until a week before Sectionals to pick their set list and only just got into the whole "team spirit" thing that the Warblers have going on.
That's my headcanon (in addition to Blaine yelling, "GAAAH!") until the episode proves me otherwise.