Fantasy Football: Kyle Orton or Tom Brady?

Orton has a new coach this week, and even though he's been a fantasy leader, the coach was the running backs coach until his promotion. RB Knowshon Moreno has had 57 percent of touches the last two weeks, and I expect the Broncos to throw the ball less with Coach McDaniels being fired. My other choice is Tom Brady, who is playing against my Chicago Bears. Conditions at Soldier Field are going to be atrocious, with game time windchill estimated at -4 degrees, and winds gusting to 50 mph. Not to mention the Bears defense has been really good this year. I think I still might have to start Brady anyway. Any thoughts?