Although Chicago's record is a much better 8-6, vs. the Packers lousy 5-9, Chicago has only outscored their opponents by 29 points this season. The Packers have outscored their opponents by 32 points. These two teams are much more comparable then their records would indicate.
After watching the 35-7 disaster last season at Soldier Field in the bitter cold, I would expect that weather is the biggest key to the game. The expected forecast from Weather.com says the low should be 3 degrees with a 10% chance of snow.
Mike McCarthy is well aware of what went wrong last season in the cold:
(After seeing the struggles of the punting unit last year, any words of advice to Jeremy Kapinos and Brett Goode?)
We still have to snap it, we still have to get it off. Rob Davis was the snapper last year, and the particular movement on the ball and handling the ball in the wind was something that factored in those situations. We'll be ready.
Two blown punts, that led directly to Chicago TDs, and an INT that was returned by LB Brian Urlacher for another TD, turned that game into a blow out.
Chicago's offense hasn't blown out anyone lately. Since their bye week at the end of October, they've gone over 300 yards of total offense only twice (at St. Louis and home against Detroit). Also, according to Football Outsiders, they are 19th in the NFL on power runs (short yardage 1st down or TD conversions). The Packers were run over by two better power rushing teams (Jacksonville and Carolina) in recent weeks. But Chicago is unlikely to have a lot of short TD runs against the Packers.
RB Ryan Grant has been getting worse over the last four games, but his best game of the season was on November 16th vs. Chicago (145 yards and 1 TD on 25 carries). RB Brandon Jackson is struggling with an injured wrist, although he is expected to play, but Mike McCarthy never gives Jackson a chance in close games anyway so he shouldn't be a factor. The Packers can't win unless Grant has a big game.
It would be a surprise if either offense did a lot in this game. Chicago beat New Orleans last week in large part due to an opening kickoff for a TD and two big pass interference penalties that put Chicago in the red zone and led to 10 points. If the Packers have solid special teams, few penalties, and no turnovers, then Chicago will be hard pressed to score a lot of points, lousy Packers' defense or not, in the cold weather. But the Packers' running game has been lousy lately, I don't know if QB Aaron Rodgers will have any success throwing in the cold weather, so it doesn't seem like an offensive explosion by Green Bay is likely either.
Without an explosion of mistakes by either team, this should be a close game with more FG attempts then TDs scored. Both teams should have trouble on offense. Turnovers, penalties, and mistakes on special teams should be the big plays of the game.
I expect the Packers to lose, since that is all they've done lately. By how much all depends on how many mistakes they make. But if they can keep it close, maybe they can give Rodgers a shot at recording his first 4th quarter comeback.