We have also noticed the drop in the summer 30/32 miles, now we have noticed a drop down to 26/27 miles, now we are starting to use the heater it will drop to 18/20 miles, when the temperature real drops and the heating on 17/18 at the very best.
In the winter I regularly use the save/charge modes and take the heat of the ICE if I go any distance.
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.