Bills have now won 4 games in a row. They are division rivals to the Patriots. This game is in Buffalo. The current spread of 15.5 points at Olympic is insane. There is someting called regression to the mean. It means that New England can not go on beating opponents on the road by 17 plus points, every game this season. Especially good teams. And in my opinion, the Bills are a good team.
The home field advantage in Buffalo is going to be worth more than 3; To the Bills this is their superbowl. To the Patriots, they are on their way to the superbowl whether they win this game or not. They already beat Buffalo once, they don't have to beat them again for tie breaking scenarios. Buffalo already has lost games and is not a threat to get home field advantage in the playoffs.
In summary, the Bills have more motivation to win, the Bills have more than the standard 3 point advantage, the Patriots winning of games by more than 17 points stopped with the Colts (a team that didn't look very good last night) and I suggest it will stop in Buffalo as well.
I am well aware the Bills running back is injured. Remember this is a team game; the blockers are still there for someone else. And don't forget what happened to Dallas when they came to Buffalo, 5 weeks ago.