I am Canadian and it just gets too cold for my fingers so I also store my batteries for long term and this is what I did last year. Bring my batteries to storage levels like the other post said, I have the DJI hub so it makes it easy, I place my 4 batteries in a ammo box (good seals) with a silica gel pack and put them in the fridge (not freezer). Then the flying bug will gets to me and cold or not I just have to fly because flying my Syma indoors does not cut it anymore. I take the ammo box out of the fridge the day before (do not open) and let it get to room temperature, the outside of the case will condensate for a few hours but the sealed case with silica packs keep your batteries dry. On fly day charge to 100% and go have fun, after the second battery flying at -20c you remember why you stored them in the first place. Here is another thing I do, when coming in with your craft from the cold, turn the bird off and leave the battery in, place the bird in a plastic bag and tie it up outside, when you will hit the humid air inside your house the outside of the bag will condensate a lot and not your craft (very very little), after about a hour I take it out of the bag remove the battery and let it air out and make sure it is warm and dry before placing in it's case with silica gel packs. Same goes for swapping batteries in the cold, keep your fresh batteries close to your body for heat and do it outside, do not go inside the house from the cold to swap your battery as your craft will condensate. The P4 can fly better than the pilot at -20c. If you do take it out in the cold don't just sit there and hover, take off a start moving, when I cruise at 30mph (50kph) as this is my usual speed my batteries run around 44c and I get the same flight times. Flick6211, don't put them too far away because on a beautiful days I bet you will sense the need to go for a run or two or three even more. My batteries have around 85 cycles each in the last 18 months and all 4 lights are on for battery life and I still get about 20 minutes flight cruising around 30mph and going over 40,000 feet total distance and land at 20%+-. It pays to take care of your batteries and craft.