The DCA method is the best for every Bitcoin investor, I would like to add something to the information you have given. Because if Bitcoin can be invested according to the DCA method, then it is definitely possible to be successful and it will be possible to hold Bitcoin for a long time.
You can buy bitcoins several times and think like you are doing Dollar Cost Averaging for your Bitcoin investment portfolio as well as believe that you will be able to hold your bitcoin a long time.
It can work or can not work, and it depends on how did you manage your finance including investment capital. If you use all money you have for investment, and you always have empty pocket after each bitcoin purchase, you will have very weak financial status and balance so that it's harder for you to hold your bitcoin. if you need money for spending, you will have to sell part of your bitcoins.