It started in penies and now is 17k. That's a return of much more then 50.000 times. To come to 1 million USD it need only 50 times of that what we is the value right now.

True, but you have to realise that once something goes mainstream the growth curve tend to slow down. The most growth comes between the mainstream and the early investor phases and i think that is around now personally speaking.
So whether $1 million is even possible, i don't know. It could happen as a result of inflation. As a matter of fact 1 bitcoin would be worth trillions of zim dollars if they were still around and something could happen to the usd that has a similar effect.
We don't know. If it does happen i predict in the next 10 years, that's as specific as i can get.