I've run with them in weather below 0dF, but not as cold as you're looking at. I haven't seen any issues with the runScribes themselves.
Something I have found is that the coin cell batteries don't perform well in extreme cold when under load. The pods have gyros, sensors and are writing to memory. By nature this creates more load on the battery than something like a HRM does.
If you're using rechargeable batteries, I would be sure to have them fully charged, or a fairly fresh CR2032 before running in extreme cold. On one run with temps below 0, I started with a CR2032 just below 50%. It didn't finish the run, but had warmed up enough to show 0% when I got home and sync'd. The next day it was back to 48% and continued to work normally since the temps had warmed up some.