It's interesting to play with the GOM. You can see how much it changes with ECO mode, and with the heat or A/C on.
You'll probably find that some routes you take are more energy efficient than others. I haven't been able to explain some of the differences.
The GOM always amuses me in the mountains. It might show 20 miles after climbing to a trailhead, and then 70 miles part way back down to the plains.
I live at a lower elevation than anywhere that I go, so the GOM reads a bit optimistically whenever I leave home. The opposite would be true for someone who lives at higher elevation than their destinations.
I've never used LEAFSpy. I think I'm happiest when I don't know too much.
Congrats--hope you enjoy the car!