Let me summarize my view, it might help this discussion.
The most important point about m/kwh is we are trying to have low cost of travelling. Let's do a thought experiment. If you electricity was FREE, how much would you care for m/kwh unless you are a travelling sales man and are always on the road with meetings at specific times. Assuming, like me you use your car for everyday things and occasionally do motorway driving, the real issue become cost/mile. Why would it matter if the efficiency is 3m/kwh or 4m/kwh. So the most important issue is how much do you pay for your electricity. Try to minimise that and the rest is not all that important.If you pay 7.5p/kwh then if you do 10,000m per year at 3m/kwh the cost is £250 (if my calculations are correct) and at 4m/kwh is £187.5. That is in a year of driving the difference is £62.5. Of course if your cost is 30p/kwh then the difference becomes £250. Still pretty manageable. So my message is turn on your heater you heated seats , radio etc etc and enjoy your fantastic car. In fact put your screen to wheel pressure so you don't even have to look at m/kwh and enjoy yourself.