Ignition locked in cold? WHY!?!?

So, I go outside today and it’s -8 w/o windchill, but -22 with windchill. I have a 2002 Chevrolet Prism (which, to those uninformed on this fact, it’s a Toyota Corolla at heart). I go outside this morning and the same thing happened yesterday, but I got it started. But the steering wheel is free to turn as if it has no electric assist, as well as the ignition is locked. I would have thought it was the whole ordeal where you whiggle the wheel side to side and it unlocks, but the steering wheel is normally the one locked. This time, the key doesn’t turn. Why?

I interpet your concern as follows, the steering wheel is free to turn but the ignition will not turn.

You are correct,normally the action of turning the key also relieves a pin in some type of lock plate,in your situation you don’t need to turn the key to unlock the steering,this is not good, I conclude the same failure that lets the wheel turn is also preventing the lock cylinder from turning.

You could let it warm up before you remove the steering wheel and explore for the cause of the steering lock/lock cylinder concern.
Sometimes it is possible to remove the “clamshells” (the covers just below the steering wheel and examine the lock cylinder/steering lock assembley without removing the steering wheel).
I would hate for you to do uncessary work when the situation is related to temperature (something sticking)I know you can’t wait till spring.

How many miles on the Prizm, and how many keys on your key ring? I’m not kidding, this may matter. How many keys?

If the steering wheel can be turned from side to side the ignition key should also work. Your car is not old enough to have a worn ignition switch UNDER NORMAL CIRCUMSTANCES, but if the circumstances are not normal everything changes. Thus my questions about mileage and the number of keys.

The steering is not electrically assisted. Power steering is a hydraulic system, and only works when the engine is running. This has nothing to do with your current problem.

Do you often have to “wiggle the steering wheel from side to side” to unlock the ignition?

On this car, the lock cylinder is physically attached to a linkage that pushes and pulls a bolt that locks the steering wheel when the key is off. That is why rocking the steering wheel in the past would free up the key cylinder, by relaxing pressure on the linkage.

You say that the steering wheel no longer locks with the key out? It can turn as much as you can, from left to right?

It sounds like something on this bolt or linkage is broken. The lock cylinder will have to be removed, and the steering column disassembled to fix it. On these cars, it can be quite an extensive repair. These columns were not designed to come apart easily.