We scored less than 20 points in four games last year (and in the game where we scored 20, against Philly, we should have scored more, but I know could have doesn't count). The four games were at Chicago (14), at home against Arizona (17), at home against the Chargers (17) and at the Giants in the last game of the season where we weren't playing for anything (17).
Probably only Chicago would meet the big game ... on the road ... outside the division criteria you've set, but that's a very limited criteria. The only other games that fall into that category would probably be at Denver, and we scored 24, and at Detroit, and we scored 30. Now, we weren't competitive, but if we'd have played decent defense, maybe we would have been.