I don't know if this has been independently tested, but if someone can produce an EV with 1250 mile range this is game over for gasoline. I suspect though this is just hype with no basis in reality.
These new cars can drive 1,250 miles without refueling
A new hybrid EV design from BYD can drive more than 1,200 miles without refueling, and two cars using the design will launch soon.
bgr.com