running lithium down to zero isn't a great idea, every time you do it, you cut the maximum charge it can hold by a tiny bit, and it adds up quickly (aswell as some other chemical changes which can outright kill the battery)

I drive the TC on daily basis  40km for 1100km now in 2nd setting approx 50kph and depending on the weather I come home whith about 16 to 25% SOC

The estimated milage is being reset every time you charge and is not learning on driving style. 

I only keep track of de SOC and outside temperature and that is accurate.