Remaining schedules are not in the Cowboys favor at all:
Washington: NYG, @ Balt, @ Cin, Phi, @ SF. I'd be suprised if Washington doesn't manage to go AT LEAST 10-6 with a very good shot at 11-5 (I think they manage to split the next two). The last three all look like W's at this point. I believe Washington will have the tiebreaker vs. Dallas. Even if Dalls catches Wash in Division, right now Wash. also has the better conference record.
Carolina: @ GB, TB, Den, @ NYG, @ NO. Although they have a game lead on Dallas, I kinda like the Boys chances of beating out Carolina. In fact, I like em better than the chances of beating out the Skins. Dallas has a good chance to win the tiebreak by virtue of a conf record (if Dallas loses to Pitt) or common oppenents. I think 11-5 is best case for the Panthers.
Atlanta: @SD, @ NO, TB, @ Min, STL. Right now, ATL has the tiebreak by virtue of conf record. Only way that changes is if Dallas loses to Pitt and ATL beats SD. Dallas likely would win the common oppenent battle if that happens.
Tampa: NO, @ CAR, @ ATL, SD, Oak: 11-5 or better IMO. Last two games will likely be W's. In a 2-way tie, Dallas gets the tie-break by virture of head to head. In a 3-way tie, TB currently has the better conference record. Not sure how that would work.
GB, CHI and Min are all still factors, but I highly doubt two of those teams end up 10-6 or better. And I think we all agree that Dallas will have to win at least 10 games to make the playoffs.
However, I believe it will take 11. I think ATL will manage to win 10 games and has a good chance to hold the tiebreak on Dallas. I think TB takes the South, nullifying the only tiebreak Dallas currently holds. I also think Washington wins at least 10 games and will hold the tiebreak on Dallas. Carolina would have to totally fall apart not to win 10 games and may well go 11-5 (as I suggested earlier, Dallas probably gets the tie-break over Carolina).
I don't think a team has ever missed the playoffs in the modern era at 11-5. However, plently have missed it going 10-6, including Cleveland last year. It's not going to be easy at all for Dallas. SEA, Balt and @ PHI are must wins. Then Dallas has to manage a split @ Pitt and NYG.