9f! Oy

I was born and raised in Buffalo NY so I remember cold like that. Remeber being the operative word. VA is cold enough for me now.
Just remember you want to cycle that Thermal Paste through some hot to room temp transitions to get it cured. Also, be aware of condensation forming inside the case if the outside air is moist. Pumping moist, cold air into a hot, dry, enclosed space can lead to some interesting electrical activity.
If you run the flex tubing so it dumps over the radiator I bet you'd get some awesome results without effecting the moisture level in the case at all. I can get that effect just by opening my window, behind the case, as the cold air drops to the floor and right over my radiator. Course the whole room eventually gets freezing as well. Your wife looks at you strangely when you put a jacket on to go into the computer room.