I think you guys are totally utterly underestimating the power usage of an electric car and the rate of charge of its batteries.
The most high-end PCs will consume around 1KW per hour, the battery inside a model S stands around 100kw of capacity. It can easily power your entire house for a couple days even if your household uses more power than average. If you're being careful with energy usage you could have lights, electric stove, fridge and the other essentials for a week from it. Gaming won't make much difference at all.
Given you can easily get multiple dozens of percentage points with a half an hour charge at a supercharging station, the less than half a percentage point that gaming would use up during this time-frame is really negligible.
And yes by just driving your car around you use all this power in just a few hours. They're way more power hungry than any household electric device including gaming PCs and heaters. After all, they're carrying around literal tons of weight.