I actually don't put a ton of stock into that Ravens game because it came on the heels of the Packers blowing what they thought was their shot at the division/#2 seed by beating themselves at Chicago (a game they held the Bears' running game in check), and the night after the Packers knew they clinched a playoff spot. They will be challenged to repeat the success they've had limiting the Bears running game in both games they've played this season, which is why I think how the Packers' linebackers play will have a huge say in the outcome of this playoff game.
Forecast for saturday night's game looks to be temps in the upper 20s after a morning of a rainy/snow mix, and pretty windy. Knowing how putrid the playing surface at Soldier Field is under even good weather conditions, this could turn into a mudder assuming their grounds crew does something stupid (safe bet) - which I think favors the Bears, but should also help the Packers' run game and slippery field conditions tend to even out what happens in the trenches.