I think the probability that the MNF wouldn't have some meaningful impact on the standings is pretty small. Seeds 1-3 all entirely depend upon it, and the AFC North might too. Unfortunately I don't think a single solution exists that is going to be fair to everyone. A tie is terrible for the Bills, lame for the Bengals, and eliminates the Ravens in the division. A no-contest is the same. A win for the Bengals is terrible for the Bills and eliminates the Ravens in the division. Resuming the game at any point both places the players in a ridiculous psychological position and disrupts the entire NFL schedule (likely placing both the Bengals and Bills at a significant scheduling disadvantage).
The NFL will have to make an executive decision, and everyone will have to live with it. Every option sucks.