Is there an operating temperature range on the SS3 keypads?

There is a limit, but where it is stated, I don't know.  The lower temperature is around 41 degrees, but people have successfully used components (not the keypad to my knowledge) at lower temperatures.  The temperature range is for legal reasons (CYA), not functional reasons.

Plus, you might have some battery issues in the keypad.

Lithium batteries work better in cold temperatures

The rated operating range is given in the manual: 32F - 120F, 90% RH.

That doesn't inherently mean it won't work outside that range. But, as sevensiamesecats alluded to, it means SS is not on the hook if it doesn't work outside that range nor repair/replace it if damaged by exposure outside that range.