Correct, if the Saints win out, it doesn't matter what anyone else does. SF and GB do play each other, so they both can't tie with us. I'm not entirely sure if the Saints have the tiebreaker over the Packers, so that might be an issue.
We won't know anything about the tie breaker with GB (if it even comes to that) until many more NFC games have been played by both teams. We're just getting to the halfway point of the season Sunday.