With the Bears clinching the NFC North, I think it's all but impossible for a Week 17 game to meet the standard required for a Sunday night flex. For example, the Eagles and Washington could theoretically be playing for the NFC East title in Week 17, but that would only be the case if Dallas loses its final two; there's no way the league would flex the game if Dallas could beat the Giants earlier in the day and render Washington-Philly meaningless (also: JOHNSON! FOLES! FOR ALL THE MARBLES ON SNF!)
Meanwhile, Indy and Tenn are playing in Week 17 and are both in contention for the No. 6 seed, but I'm fairly certain Baltimore can't be eliminated next week, which means Indy-Tenn can't be flexed without knowing the result of Ravens-Browns.
Looks like we'll be getting a pre-New Year's Eve night off a week from Sunday. Take advantage of the opportunity to reacquaint yourself with your family.
ETA: I was wrong. If Baltimore loses @ LAC next week and Indy and Tenn both win at home (over Giants/Washington), then the winner of their Week 17 game would be 10-6, while Ravens could only get to 9-7. Since all three of those Week 16 outcomes are what would be expected (FiveThirtyEight says both Indy and Tenn have a 74% chance of winning next week, while Baltimore has only a 34% chance), I'd say there are decent odds that Indy-Tenn will be the flex game.