On those days that I have to add some range due to either necessary driving during the day or low outside temperatures, I would love a GPS (either embedded or 3rd party) that would route me for best cost/range performance. Neither the option for my 2011 Leaf nor the option for my Garmin Nuvi give me the ability to optimize range.
For an example, the default for most GPS units is the faster method. Taking a beltway around a major city to get to the other side may get me there faster, but it may also add 15-20 miles to the trip. Going through the city may take me longer, but it would keep me at optimal performance for an EV (unlike gas engines that suffer severely from stop and go traffic) and help me get there with less anxiety.
On most days I barely get to the halfway point on my battery gauge, but there are THOSE days when it just doesn't work. Last week I got called to help my daughter get her car because she was 10 miles short of getting home. The trip to and from her destination added almost 30 miles to the distance she had to travel. Again, the straight line would have taken longer, but it would also have gotten her home without the tow and charge. Fortunately, NISSAN did pick up the towing charge.