I'm very interested in buying, but have to wait a few months to do it. I do have a few questions. I live in Colorado. We have mountains and the temps go from -20 in the winter to 100 in summer. So to begin, how is the power in mountains? Does the car keep warm inside during the Winter and cool during the summer? If you are heating or cooling the car does that greatly change the MPG? Thank you for your input!