If I'm not mistaken by 2038, we could have reach 99% of all bitcoin mine. So that alone will speak how the price will move after that. Because the rest of the 1% will be mine up to 2140.
This will happen before 2038, sometime around 2030 during the sixth halving period. Namely, at the end of the fifth halving period, the total amount of mined BTC will amount to 98.43750011% (2028), and sometime in the middle of 2032 this amount will exceed 99% (99.21875011%)
https://en.bitcoin.it/wiki/Controlled_supply
I think it's pretty frivolous to talk about the price expressed in millions while even $20 000 is an insurmountable obstacle. It’s not that I don’t want that to happen, but for the vast majority of investors, Bitcoin is still a very risky and quite exotic investment. For such crazy prices we need trillions of dollars, and now the total market cap is worth just over $300 billion ($0.33 trillion).