This winter has been brutal, and recently I have been experiencing stiff steering when it gets really cold (like 10F). It's not super stiff and the steering becomes normal during warmer days
Also no warning lights of any sort and all four tires are at 38 psi when cold...

Any idea what could be wrong?

 

First time hearing this... something is frozen? I don't know.

 

It takes a while for that fluid in your steering rack to warm up and the viscosity of it to become more fluid than solid. I don't think anything is wrong with your car.

 

There's fluid in the electronic power steering? Is it some kind of lubricant?

 

^Yeah, 2IS models have electronic power-assisted steering, No fluids. Nothing I can think of to help you in situation besides no quick movements until at operating temps.

 

I'm in the northeast too, and have not noticed this with my car. 2009 is250 AWD

 

Update: so it turned out to be the battery. The oem Panasonic tested 12v but only 380 cca. I put a new one in, and the EPS is back to normal. Seems like the power steering on the 2IS likes to act up when the battery is about to go bad.