This is completely untrue. The current EPA standard is only a few years old. It happens to be the toughest standard in the world. Other testing mechanisms give higher ranges so you can complain all you want but it is the best. It is one of the few areas that the US leads the world anymore. It is true that the testing does involve lower speeds but then a correction is done. I find that the correction is still overdone for aerodynamic cars meaning cars with better aero do relatively better than EPA at true highway speeds.
If you go 55 mph, you should exceed the range.
Tesla Range Table - Teslike.com
For those that don't want to click it, the range at 55 mph of a LR with 18/aeros is 412 miles. Note this is the highest of any Tesla including S 100D. I have 75k miles on a 70D and I can absolutely exceed EPA range at 55 mph. My breakeven speed is 69 on a warm day - meaning I exceed EPA below that. I mostly drive 80 mph on trips but have different routes with different speeds if the need arises.