cold air drafts

Now that the weather has gotten colder, here in Michigan, I notice a draft from the drivers door. On longer drives I find myself resting my left foot flat on the floor, instead of on the "dead pedal" spot. Within a few minutes my knee, that's next to the door, gets quite cold. I think that the air leak is around the door handle and wonder if anyone else has this problem and has found a solution. I've tried to direct the side vent toward my knee but it won't point low enough.