We all know first hand that high speed dramatically reduces range. In the case of the nextgen Roadster, it won't get 620 miles of range at high speed. Anyone care to estimate the actual range at 200mph?
if 620 miles is at 70mph, than cubing the speed increase to get the power increase shows the battery will deplete 23 times faster, but you are driving faster. My back of the napkin calculation says ~75 miles.
Cooling the battery and motors may be the limiting factor, rather than kWh
Don't think anyone cares. Those top speeds are just for the (all important) bragging right. Those tires on Bugatti Veyron will last 15 minutes at top speed and cost ~$45K for a new set.
assuming 620 miles at 60 mph and that 1/4 of drag is rolling and mechanical, linear with speed, and 3/4 is air drag, quadratic with speed, gives a rough eatimate of 80-90 mi at 200 mph. or maybe 25 minutes.
your mileage may vary.