The best way for an amateur like me to confirm this is to drive it for a while in cold temps. Range loss in the cold is MUCH less with the Y. My brother in-law has one and he says using the heat barely consumes any more power than the A/C. I've read that a lot.
If I had the car wide open I'd have no idea what I am looking at. Real world conditions will give you an answer!
What would a good consumption rate be to look for? (if anyone knows what the Model Y's winter kWh/km rate is)