For what it's worth... I fly all kinds of electrics not just drones ( although I guess everything now is considered a drone ) so I have between 40 and 50 lipo's all sizes and I keep them all fully charged all the time, but I keep them in a refrigerator ( small one from Wal-Mart). This slows down the chemical reaction that would normally make a lipo deteriorate if kept fully charged at room temperature.
That being said, you can't just plug one in and go fly. The same cold that saves them stops them from performing and you will get very short flights and damage the cells because of high resistance when cold. They need to be warmed up before use. Hobby King sells a lipo bag that has a heater in it to warm up batteries like this and for people that live in very cold climates. It can be set to different temperatures and plugs into the cigarete lighter socket in you car so by the time you get to your flying site they are ready to go. You can also run it off of your power supply at home. I can't remember but I think lipo's operate a peak performance at around 90 degrees F. Maybe someone else can chime in on that. Anyway, thats just how I do it, not saying it's right or wrong.