Carbon frame stored out in garage, it gets below 32f, inside instead?d?

No, not at all.
The main and about the only mechanical concerns related to cold, but rideable temperatures is freehub lube getting sticky preventing the pawls from engaging, and any lube/moisture in the cable sheaths causing poor shifting and preventing brakes from disengaging.
Your bike is cold and lonely...bring it inside and pour it a drink!

I rode a carbon bike in 21° temps yesterday. Didn't hurt it at all. A plastic bike with a service life of 5 to 10 years spending time 'sitting' in the cold isn't going to damage anything. Condensation, on the other hand, is something to think about.
Carbon fibre seems ok for airplanes at what -70C?

But just in case, I took the magnesium bike out in 15F temps yesterday.
Carbon fibre seems ok for airplanes at what -70C?

Carbon fiber was [is?] used extensively in the aerospace industry, e.g., the satellite radio antennas on the Voyager spacecraft were made of carbon fiber. Outer space temps are typically 2.7°K (-270.45°C or -454.81°F) so I'm pretty confident the guy's bike is okay. :)

I've been riding a CF bike through the winter for the past 9 years with no adverse effects...but I've only been riding on planet Earth, so not the most extreme temps.