I have an Rpi2 out in my garage, today it is about 35 degrees out, and the CPU temp is 28.2c.

Is this too cold, how cold is too cold?

Is there a min I should be concerned about, and what will happen if it gets to cold?

I know generally speaking, the cooler a computer is the better off it is, but I would think that at some point it has to get to cold? What would happen if it get to cold? would it just shut off?