My experience so far (I've only had the eGolf 6 weeks now).
AC and heating appear to eat about 2kw, which means given I have about 220km range normally, or about 2 hrs at highway speeds on a 35kWh battery, It would mean with the heater or AC on, I'd drop to a 31kWh battery, and lose about 12% range. I can live with that.
Having the car automatically set the temperature before you go to work and come home is pretty damn awesome. This time of year theres not much to do in the morning, but in the evening having the AC auto come on before you get to is pretty cool.