How many BTC will make you a fiat millionaire ($) in 5 years? Why?
As I doubt bitcoin price will go totally insane in the near future I would say you will need more than 1.500 - 2.000 BTC to reach million dollars threshold.There is probably no way that we will see price increase after the halving so it is hard to predict bitcoin price after that.
Even at todays BTC price you only need 1000BTC to be a millionaire (1000 x 1000 = 1.000.000)
I doubt BTC will drop to 500$, in which case you would need 2000BTC