We remember that Vikings game as the Josh Allen coming out party, but looking back at the stats it was as much on the Bills D as on Allen. Milano had a pick and a sack. The Vikings were held scoreless through 3 quarters. If the Steelers are able to do that to the BIlls (doubtful), then they have a really good shot to win the game.
Also, the huge line was because the Bills had been awful through two games and it was only game 3 of the Kirk Cousins era in Minnesota. There was still hope that Cousins would turn to be elite. Spoiler alert: he didn't.