At that point, we should be celebrating if one bitcoin was at 1 million dollars, huge win for the world lmao.
Anyways:
If at the high price, alot of wasted energy today would be converted to using mine bitcoin. So while alot of energy, it also won't be wasting much energy. POW after all is a way to convert energy into money.
POW is still a natural force distribution mechanism as miners have to sell their bitcoin to pay their bills after all while in POS we are keeping the coin more and more.
I argue POW for bitcoin at least would remain as kinda like a global standard.

Funny this argument is also at play that since bitcoin focus is offchain, there wouldn't be any money for miners thus miners will leave in waves thus also making POW bad. :P