Re: -13F (-25C) coldest I've ever seen
Think of it as a really good test for your plants. What is your snow cover like? How long was it below -20C?
My garden hit -30C last night (thermomter read -29.4 but it's under a cover; so may have been colder). The new farm also hit -30C and Toronto stayed at a tropical -22C last night.
Not enough snow here, it'll be a good test for the 'marginals'.