Imagine how much money would have to flow into the market for bitcoin to reach $1M - surely that's not a small amount, right?

Of course, you can be that optimistic if you have already bought or have bitcoin in your wallet - so your job is just to secure your wallet and wait for the estimated price. It will take you a long time to get bitcoin worth $1M per coin - it's never as simple as you imagine. Personally I don't believe bitcoin will be worth $1M per coin yet - that's too high to be true in the next few years.