That you can safely fly your quad.  I live in Ohio and I had a guy ask me if I could take pictures of his house once he gets his xmas lights up after Thanksgiving.  It could be decent, or it could be cold so I wanted to see what extreme temps these birds can handle.

0*C~40*C is what's in the Phantom 3 specs, & for the iPad Air 2 it's the same.

Keep your batteries warm, and let the bird warm up in a static hover for a minute, before you fly.

RedHotPoker

Obviously, once you get a battery in your PHantom, your flight time will most likely be somewhat reduced relative to what you would get in warmer weather. However, based on my experience with camera batteries (Canon DSLR) you should still have plenty of time to get some worthwhile videos.

As RedHotPoker pointed out, when you're not flying, keep your battery (and any extras) in as warm a place as you have available. Cold weather is really hard on just about any type of battery.

Art - N4PJ
Leesburg, FL