The answer to that question is "YES", but the new question is "When?". And that's what we don't know yet. But you can be sure it will happen, and it's possible because our financial system allow us to get in infinite debt, that way money becomes infinite, and when you understand that then you will realize how the bitcoin price has no limits at all.
The answer should not be only yes because there is every possibility that Bitcoin may not reach to that extend because another technology may come up and bitcoin get scrapped out for the market, but as long as bitcoin is into existence and it gathers influence across all the nation there is every possibility that the price might be reach 1 million but right now we are looking at the price being up to one hundred thousand [100k]. It is obvious that the more bitcoin gather influence the more investors come in into cryptocurrency and the more cryptocurrency especially Bitcoin get increased because of investors.
Indeed Bitcoin can achieve this remarkable milestone but 15 to 20 years are way too longer IMO and it's really difficult for people to hodl something in cold storage for such a long time as just one hardware device can ruin your life long saving if you lose it. I would say let's split our investment into long term hodling and depending on market flow as well. There is no harm in buying Bitcoin in the bear market and selling them off during the bull run or even when it gives a decent amount of profit and repeat the cycle but this would require a lot of patience where many people would definitely fail.
investors who knows the rudiment of cryptocurrency especially Bitcoin no quite well that the more the Year comes up or come close the more Bitcoin have more people who is adopting it and the more the market of Bitcoin increase so therefore people would like to hold Bitcoin knowing that the more the year are adding the more the prices getting increased so many people will like to hold to their Bitcoin if they are opportune to buy now or they are opportune to buy in the bearish season.
Remember that the holding the Bitcoin have advantages and the advantages comes from the duration due place your Bitcoin and also when you purchase your Bitcoin because many people who foresee the development of Bitcoin and the purchase during the time the price was low, right now bitcoin has made them to become a billionaire based on the price continue to rise, but my advice to a beginner is to target when there is a bearish season and also ensure that the purchase and hold until the bullish time.