Winter has hit hard here in Western Wyoming. The last 2 mornings have been hovering around -30 at our house (We're finally in!). Below is a list of the (many) layers I have been wearing on my morning runs. Obviously the extremities and nether-regions need special care at such cold temperatures.
Super-Sub-Zero Gear List
Black Diamond Wool Weight Liner Gloves
Black Diamond Access Mitt
SS Runshade Top
Long Haul Runner Shorts
Soft Shell Pants
2 pair of wool LW endurance socks
Brooks Launch shoes
This set up offers plenty of venting options and I was very comfortable (and very frosty) for about an hour-long run. Whatever it takes to stay off the dreadmill.