So i'm not really worried about my Phantom 3 freezing up but rather my iPhone 6 plus shutting off. Even in 25 degree weather my phone will go from 50% down to shutting down in a matter of 5 - 10 minutes. I have been searching for cases that will keep it warm but I am not having any luck. Anyone have any suggestions for a good case that will keep the phone warm enough to function? I also just purchased an iPad Mini 2. Has anyone been using that in cold temps with success?