This post is worse. It's easy to get any voltage you want out of a big battery pack. And it's pretty easy to convert between voltages. The hard part is sustaining whatever max voltage your motor can accept, which is a matter of power. If your motor is big enough, and your electronics are at least competent, the limiting factor is the power your battery can supply.
Edit: Like, a Model S battery supplies about 330 volts and rearranging the battery cells in a simple way would make it supply 4000 volts at lower current. You could replace the coils in the motors to accept that newer voltage and get very similar performance but with significantly higher chance of electric shock.
(Disclaimer: not an expert)
The reality is more complicated when you can vary the motor design, Kv, etc.