As mentioned in another thread, I think it's quite likely that Garoppolo could struggle in a game with the temp as low as it will be. The only game that Garoppolo has played this season in sub 40 degree temp, he was awful. And in that game it was upper 30's.
And as
@Pokerbrat2000 alluded to, has he ever really played in a game where the temp will be in the teens? I know he sat on the sidelines a lot during Foxboro temps, but he was never the guy on the field pulling the trigger.
Another issue with him playing in the cold is his thumb. You saw how it potentially limited Goff last year, although somewhat different circumstances.
The whole key to making sure that he struggles though will be shutting the run off at least enough to make him have to throw it more than 6 times like in 2019. Because if he is forced to throw as much as a normal quarterback throws, he's going to give the Packers opportunities for turnovers.
Find a way to get him in enough long down and distance situations, and let Clark, Gary, Smith, etc. hunt.
They are also a little banged up defensively. I fully expect LaFleur to take advantage of this.
I didn't want to play them initially, but I'm getting more confident by the minute.