I think McCarthy out smarted himself this week.
First with the cold, I would think McCarthy tried to keep his players fresh by practicing inside, all a part of his "rest and recovery" strategy that has worked so well (I'm not being sarcastic, it has worked well). But in this instance, the players practicing in the could would've been best.
Secondly, I think McCarthy/Sanders took the Bears rushing attack lightly. I mean I hope they did, because if they planned to stop the run and still didn't, it's something to worry about.
Finally, I read that McCarthy switched around Coston to LG and Spitz/Colledge to RG because of potential match-up advantages. Continuity works wonders, as McCarthy realized with the running game.
Basically, McCarthy WILL learn from this. I am sure of it. I'm happy the Packers got destroyed in a meaningless game, allowing the players and coaches time to get things fixed.