Wear that big fuzzy hat with the ear muffs that ties under the chin and you'll be fine. The tailgating might be chilly but I bet there will be a lot of body heat in the stadium to counteract the cold.
You're going for history here.
Of course that's easy for me to say. I'm going to mow in the morning (last yard work of the season... YEE HAW!) and then settle in to watch the games from the comfort of my family room.
Wherever you are, I hope you enjoy the game. Go Lions! go.blue.ksquared