For me Bitcoin has been my 100% portfolio and up to this point, I am glad that I choose that part even though Bitcoin price has undergone a lot of changes lately, my BTC vs $ balance has shown green and also red-negative movements which is a pointer to the activeness of bitcoin volatilities.
Knowing that Bitcoin is volatile in DCA pricing and also having a balanced market that shows not too much of a sign, e.g. 50% price movement within a few hours which is a sign of pump, or a drop in price significantly below 50% which is a sign of dumped.
Bitcoin has a cycle to help calculate its movement unlike those altcoins that have high centralization, subject to pump.
Well bitcoin is more stable than other altcoins next to tether. It's nice for ou that you already know what asset make sense for you the most holding and it's 100% btc on you. It always lie down on how much level of trust do you have of what you are holding. Because if you have too little, tendency is you will sell it on fake dumps.
I also think that you have a very clear timeline which sets the tone for you not to be fearful when market is tanking but to DCA. You had a plan laid out which separates you from other losing trader/investors. Knowing that the market move in cyclical manner would be a good mindset to stay on your lane and continue following your plan until it is achieved.