In reality, if I manage to win something that significant, I wouldn't invest all of it in Bitcoin, I will probably invest about $200k to $300k in Bitcoin and use the rest to set up a real-life business for myself so that I can keep getting money from it because Bitcoin might be profitable but it can't be compared with a profitable real-life business because that will always be earning you revenue regardless of the season or the time in the year, so that would be my first priority.
But, since it is a hypothetical question, I would say that the best way is probably to keep buying after every price interval, like if Bitcoin drops a thousand dollars, you should go ahead and buy some, once it drops a thousand more, buy some more, keep doing that until you exhaust your capital but make sure that you are always buying below your last buying price.
I think its perfectly reasonable to put some of your winnings into Bitcoin and to start a legitimate business at the same time. Your familiarity with both the cryptocurrency industry and more conventional business channels bodes well for your plan.
You make some valid points, such as the suggestion to consider buying Bitcoin at the end of each price interval. To make the most efficient use of available funds, one can consider purchasing items in descending price order. My only concern is that the plan seems a little too straightforward. Yet, it seems that sometimes the simplest solutions are the most useful. Its possible that wont be an issue, but Im still curious. Anyway, I appreciate you sharing your opinions with the community because they are certainly thought-provoking.