I'm noticing I lose about 2 to 3 miles of range per day of non-use even when the car is plugged in. For example, I get home from work on a Friday and plug the car in to charge. It charges to full (er, to the suggested 90% full) and I just leave it plugged in. I don't drive anywhere all weekend. Going to work on Monday morning I unplug the car, get in and notice the range has dropped around 5 - 6 miles. Sometimes more. Is that normal? Is it because it's winter?