Only need to look at the different wins for us and Seattle
Seahawks:
Miami
Denver
Arizona
Atlanta
Chicago (assuming they beat Chicago next week - if they don't this is all moot)
Rams:
Vikings
Bills
Saints
Raiders
Niners
Currently: we are leading 39 wins to 35 amongst those teams.
For this scenario to play out, both the Bears and Cardinals lose next week (if either of the opposite happens, this situation is moot)
We could clinch next week if the lead in wins goes from 4 to 6 (since there are only five teams in question, the most games Seattle can make up would be 5). We already know Chicago and Arizona wouldn't be winning in this scenario - for the rest we have:
Rams side:
Bills - home for the Jets (W)
Vikings - home for the Packers (toss up)
Niners - home for Detroit (L)
Saints and Raiders play (one W)
Seahawks side:
Miami - at the Browns (toss up bc of the cold)
Atlanta - at Washington (L)
Denver - at Bengals (toss up)
If we end up +2 from that on the week, we will clinch. Our best shot is for the Bills and Vikings to win which will give us 3 on the week (counting the one we get from Saints/Raiders) and the. For the Falcons and Broncos to lose - if that happens, we clinch.