I don't think if it is possible for someone to purchase btc and hold it for 13years,who knows if the unknown "death" will still keep the Person till then, not every risk are meant to take,some risk are very expensive. holding coin for just 5years is still difficult talk more of 13years, although making a Long term investment is very good but not this far.
It is very possible for someone to hold Bitcoin for even more than 13 years. I believe there will still be some people who accumulate Bitcoin since the early existence of Bitcoin, yet they are still holding onto their Bitcoin. If we should always be thinking of death when it will occur, I don't think even tomorrow is worth risking because even tomorrow is not promised, so we just need to stop thinking about death if truly you want to be a successful person in this life, because if you are to be planning death all the time, even property someone will not think of owing.
It is not that we will not have a plan for death, but when it comes to business or investment, that should not be our focus. Our focus should be like tomorrow is a promise; if not, you will not carry the risk that is worth carrying to achieve your dream. Just me, who has a plan of holding Bitcoin for a long time because I know death time can come any time I show my close and trusted friend where my private key has been hidden so it can be told to my parents if death later won, but not because of death, I will not take some risk worth taking now that later I will be regretting why I did not take the risk.