If you truly believe that bitcoin is the future, buy the dip with fiat that you can spare to not use in the next 3-5 years (even longer).
Better to have some btc as it's historically appreciating vs fiat. And it's really portable, no one can seize your bitcoin and you can send something of value anytime anywhere as long as you have an internet connection.
3-5 years that's really long and that's a good example of long term hold.
When you can hold at that period and you survive, that means you really believe in crypto as the market is very volatile, even in just a short span of time anything could happen, but of course at the end of the day, this all depends on your target.
For example, you bought btc at $8k now, and your target is just to sell it at $80,000 (that's 10 times), and if that will be achieved in just one year, just don't hesitate to sell it regardless if you heard some rumors that it could rise further as greediness sometimes is our biggest enemy.