If Green Bay wins out, Pacers win #1 seed by virtue of best overall win/loss record
If the Cowboys win out, Tampa Bay wins out, and Green Bay loses 1 game, there will be a 3-way tie at 13-4 in the NFC. Cowboys win #1 seed by virtue of best conference record of 11-1 vs. Green Bay (10-2) and Tampa Bay (8-4).
If Cowboys win out, and Green Bay and Tampa Bay each lose a game, then Cowboys and Packers will be tied for best record in NFC of 13-4. The Cowboys and Packers have 6 games against common opponents (Saints, Vikings, Chiefs, Football Team, Cardinals.) All 3 of Green Bays current losses are against common opponents (Saints, Chiefs, Vikings), while the Cowboys have only 1 loss against common opponents (Chiefs). If the Cowboys win out, and Green Bay loses to the Vikings, the common opponents record will be 5-1 for the Cowboys, and 2-4 for the Packers. If the Packers lose to either the Browns or Lions, then the common opponents record will be 5-1 for the Cowboys, and 3-3 for the Packers. So the Cowboys would have both the best conference record of 11-1 vs. Packers record of 10-2, or best record vs. common opponents. Cowboys would get #1 seed.
If the Packers lose 2 games, and both the Cowboys and Buccaneers win out, then there is a two way tie at 13-4 between the Cowboys and Buccaneers, and the Buccaneers win the #1 seed by virtue of Head-to-Head matchup from week 1 of the season.
Bottom Line: Cowboys need Packers to lose 1 game, and then win out to get the #1 seed. Or they need both the Packers and Buccaneers to lose 1 game, and the Cowboys win out.