I am trying to figure out the practicality of the Tesla in my life as our primary car for roadtrips, etc. I know that the MPGe by the EPA is 89 (yes, YMpgMV), but I am wondering about MPGe in hot and cold environments. What should I expect in the summer, with AC on much of the time? What can I expect in the winter with heater on all the time? What would someone guess is an average MPGe for a car in Boston, which has hot summers and cold winters?