My month-average is quite a lot higher than my trip-average. On days where I am driving within range I don't care much, and shorter journeys etc. are also not representative - especially in Winter when there is a signifcant power-penalty starting a journey (even if the car & battery has been pre-conditioned)
Of course not everyone's 200+ mile out-of-range journey is highway on cruise control ... mine invariably are. In our Winters I am 20% higher in February than best (not too hot) summer day.
My advice to people thinking of buying a Tesla is to use
A Better Route Planner, pick the model, set the temperature (once for summer, again for winter) and perhaps fiddle with the other settings, and then pick some actual range-challenging journeys and see whether they would get there, and if not how long they would have to "refuel" (supercharge in Tesla's case, but once CCS is here it will be "similar" for Jag too)
ABRP seems to be pretty accurate (data is collected from volunteer owners), and now also includes Bolt and Ampera, and no doubt others too in future. Once it has Jag data I think that would help , but in the meantime even choosing a Model-X 90 (no longer made, but similar battery size) and compensate by setting whatever Wh/mile seems like a good guess, should give a reasonable stab
(the video was 441 Wh/mile, I think production will be better than that pre-production; 290 is granny driving, 330 would be very good. I am 330 in Summer with some road work / traffic 50 MPH bits, 350 at a steady 75MPH cruise and 370 at 80mph, and mid winter 380 - 430 on highway cruises)