I have updated the graph above by adding a new data point and also made the graph below for the energy cost for the initial heating to increase the temperature when you did not preheat the car (HP = Heat Pump, RH = Resistance Heater). More details can be found at http://www.ioniqforum.com/forum/234-hyundai-ioniq-electric-ev/6393-heating-ac-what-power-used.html.