For those selling on the way up, I would also consider selling smaller amounts, and never going 100% fiat (which means never going completely out of BTC), even if there might be some who will choose to sell large amounts of their BTC on the way up.
My own personal strategy is to sell ONLY a small percent for each time that the BTC price goes up (so I am selling even less than .5% for every 10% that the BTC price goes up.. .. even though there are some folks who have recommended selling 10% for every 100% that the BTC price goes up, such as in:
Rpietila's (Risto) 2013 Thread entitled:
(SSS) - A Sane and Simple bitcoin Savings plan Exactly it is not nice to sell all the BTC and empty the coins in your BTC wallet and as that you are not a Bitcoin holder but a Fiat holder on Millionaire or Billionaire. Then later the person would be struggling to buy Bitcoin again and start from the beginning again. Instead as JayJuanGee said, selling a unit to solve the immediate problem is the best way to be a good holder of Bitcoin. Because there are some time that you might need BTC to solve issues online and if you don't have Bitcoin at that time, you would still buy again, to the transaction so it is better you sell small and keep the rest for future use.
... so you could have various price points in which you sell those BTC in 2023 (or maybe at some future date), and if you sell all of your BTC, you may well end up struggling to figure out how to get them back. Whether you are able to buy back your BTC at the price that you sold them might be another question... and whether you are able to invest the value of those sold BTC into something that is equal to or better than BTC is still another question that you will face with levels of uncertainty.