You probably know abetterrouteplanner.com
It is probably the best tool to plan a route, and to optimize where to charge.
It has a live function, which allows to adjust with the real consumption of the vehicle, by connecting an obd device and soft like EVNotify or Torque Pro.
Why not having this function with OVMS?
On abrp forum, it is explained how to send data:
What do you think?