BTC can be $1 or $1M. I'm leaning towards the latter, though. I have NO faith in the USD...
Regardless of your faith in the USD, you would need to have some MAJOR faith in bitcoin if you're going to claim that bitcoin can be 1 million usd. While I do believe bitcoin is very influencial and unique in the sense that it was the first original cryptocurrency, I don't think it has enough power to reach such levels. The only time I'd see something like that happening would probably be in the next 2 decades, which even then is probably going to end up with some newer crypto taking the place of BTC as the face of all cryptocurrencies.