When a navigation route is active, show a number on the speedometer, which is "Average range last 10 km" minus "Distance to go". This would give you a quite good estimate whether or not you can make it to your destination without running out of power. Or alternatively, how many extra miles/km you have left to proceed from destination to a charging station.
During my Autobahn trip through Germany, where speed can get maxed out at times, I used just that calculation - yet I had to have the energy screen and nav screen up at the same time, and do the math while driving. It should also take elevation into consideration, both from the last km driven, as well as how much ascent/descent from present position to destination.
This is why the result of that calculation, shown in the speedometer, allows me to forget about calculating and I can bring up any screen I want. "Typical range" displayed is useless if you are going 100 mph.