That's with a megacharger not a supercharger, there are no megachargers deployed anywhere yet. Megachargers are 1600 kilowatts vs 120 kilwoatts for a supercharger.

A charging station with 10 megachargers going at the same time will draw as much power as a small city of say 10,000 homes.

A municipality with only 10,000 homes isn't even approaching city status, more like a small town... but I get your point.

https://en.wikipedia.org/wiki/Settlement_hierarchy

Is that possible? Assuming 500 miles of range at 2kwh a mile is a 1000kwh battery, charged over 30 minutes, is 2 megawatts, if the voltage is the same as the supercharger (480V) requires 4000 amps...

Google says your average powerline carries 10k amps.. so it seems within reason, but it would require some power upgrades ;)

Power = amps × voltage . So no. They are 10kA × 3kV (well, depends on the line), so that gives us 30MW.