Out of curiosity, how do you dress for those conditions, and are there any circumstances under which you won't ride?
I don't ride once my wife finds out it will be colder than -25C, you really should not ride for in -30C unless you have modified your bicycle. Also due to the lack of moisture it is not as bad as it sounds.
Hands, feet, and head need the most protection. I use insulated MTB boots with SPD's , I use lobster claw mitten s so I can brake with 2 fingers and still grip the handle bars. When it is super cold I keep my head warm with a balaclava and a downhill ski helmet with goggles. Most of the time instead of the ski helmet and googles I use a normal cycling helmet with a balaclava and cycling glasses.
As for the body I wear a thin pair of summer big tights with a chamois then a heavy pair of lycra trouser with wind blocking front panels. On the top I wear a long sleeve under shirt, a winter cycling jersey , and a goretex cycling jacket.
The risk at -30c is that the freehub wont work. After about 10 minutes into the ride the cassette fails to "catch" and you are then stuck at the side of the road able to peddle but unable to go anywhere. I once tried to warm the cassette and chain using a cigarette lighter, shockingly chain lubricant burns quite well I had to use snow to put the fire out.