Again, look back at what happens when a team loses their stud QB.
Anyone remember Bob McGinn's infamous "Without Rodgers, Packers are still an 11-5 team" or whatever it was? Then he goes down and they are quite literally one of the worst 3 teams in the league. You need a QB in the NFL. If the rest of your team is strong, you at least need somebody like Baker Mayfield or Derek Carr or something. We are seriously trotting out Malik Willis as a starter.
So yes - I think they will be fortunate to win a game in the next 3 weeks, given that Willis is playing and he has been in the offense for like 2 weeks. And I don't think it says much about how good or bad the rest of the roster is. You simply need a good QB to do anything.
As far as the Packers defense I won't hold my breath. I have seen the worst of the worst carve them up over the last decade so while I hope you are right, my expectations are not very high especially after seeing guys run free in midfield and the defensive line get gashed up the gut again.