To add to what I said earlier, I'd be very comfortable with our playoff chances if we're no more than 2 games out of the division lead when Romo returns. I still think we'd have a chance if we were 3 games back, but I think our chances would be much lower. 4 or more games and I think it's too much to overcome. Giants are tricky because they played an extra game, so a 2.5 game lead could turn to a manageable 2 game or a harder to manage 3 game lead.
That being said, let's look at each team in the division:
Commanders. Currently have a 1 game lead. They play New England next week. If they lose (which I'm almost certain they will) they can't possibly have more than a 2-game lead when Romo returns. Plus, we play them twice so they don't scare me at all. They play the Saints in two weeks.
Eagles. Currently have a 1 game lead. Cowboys vs Eagles next week can be very important. A win for us would tie us up and make it so that Philly couldn't possibly have more than a 1-game lead when Romo returns. A loss would put us 2 behind, could threaten our tie-breaker over them (and the rest of the division), and could put us potentially 3 games out of the division when Romo returns. They play the Dolphins in two weeks.
Giants. Currently have a 1.5 game lead. They don't have their BYE until after Romo returns. They play the Bucs next week and the Patriots in two weeks. Like I said earlier, I'd be very happy if the Patriots could help us out by destroying our whole division. A Patriots loss would guarantee that NY couldn't have more than a 2.5 game lead over us. Fortunately, they have their BYE the week Romo returns against the Dolphins, so if we do our part, that 2.5 game lead will be a 2 game lead.
So, in summary, let's hope the Patriots continue to destroy the NFC East. This game against Philly is very important because it can prevent Philly from running away with the division before Romo returns. Giants have their BYE after Romo returns so it'll give us a chance to come within a half game. And we play Commanders twice after Romo returns so I don't really consider them a threat.