Hi, Given the discussion we've had in the past, I thought it a good idea to track my range and temperature relationship. I used the range remaining when I drop my kids off at school, and return home. This consistent route, plus recording my range remaining, outside temperature, and if the seat warmers were on or off (they were always on), shows that there is abut 15% of range "lost" (not available due to cold "leak") over a 20degree Fahrenheit range.
The curve is linear over the temperature range of freezing (30 degrees is lowest observation) to 50 degrees, but I am sure it curves at some point. For better or worse, I am moving 3 miles away next week, to a house with Solar, and modern look... so the experiment is over -- which is too bad, because I wanted to track it up to 90 degrees. Maybe I will start the experiment again from the new house.
Enjoy the data.