$100k is a logical price for now. But for $1 million? I have nothing to say. It will probably take at least another 15 years and we can talk about 1 btc = $1M
It might go to $20,000 again First (Unlikely), but it will get to $1,000,000 at some Point.
No it won’t fall that much low. This is because once Bitcoin fall in price, many traders will start buying it as they will be able to get the coins in comparatively cheap price. Now we know that Bitcoins are limited in numbers, hence when more people will buy the coins, it will increase the demand to accumulate the coins and now for fulfilling the demand, the price will go up. So we might not see low price like 20k usd, but yes 1 million is possible due to this supply and demand effect.