Honestly if we just replace Free and find dedicate tons of resources to the defense I'll be ecstatic.
If you get QB play at Romo's level, you are almost guaranteed to make the playoffs.
UNLESS
You allow the other team to be effective passing the ball. I went back a few months ago and listed every QB who has posted a QBR for the season at Romo's level and whether or not their team made the playoffs. They almost entirely did - unless their team was also ranked near the bottom of the league in QBR allowed.
If we want to win, the effectiveness of our pass defense has WAY WAY WAY WAY WAY WAY more to do with it than whether or not our Oline is competent. That should be almost our entire focus. Romo's entire time in the league I think we've been top 10 once. All we did then was grab the 1 seed.