Typically wet and sloppy footing benefits the offense.
On defense you have to react to the offensive player, and use quickness to get around blockers. Rodgers has been on fire lately so color me a bit worried here. Also, snow negates a speed advantage. This is where losing Earl hurts us. Earl's instincts have him at the right place at the right time where Terrell uses his speed to make up for any mistakes or lack of instincts.
That said, it will also help our OL. If you give Wilson time, he's going to hurt you...bad. Looking at our offense, we have way more talent than the Packers do. If Russ can put the ball on the money, we'll outscore the Pack.
Theoretically anyways.