You should have a long-term plan to invest in Bitcoin so that you can grow your wealth, but we can never determine the value of Bitcoin, however, if you have money left over from your income source after meeting the needs of your family, you can invest in Bitcoin regularly or weekly or monthly according to your ability. In this way, if you continue to invest for a long time, your investment will start to grow stronger.
Consider Bitcoin investment as a type of savings, which can be called Bitcoin savings. Set a goal and keep chasing that goal consistently. How long your savings journey will be depends on your goal, but at least keep saving for a cycle (4 years). There is no specific time limit on how long you can extend it, in this case you have to prioritize your goal. It is your sole decision whether to extend your savings journey or stop after achieving the goal. One thing that is advisable is that never sell the entire investment.
If you perceived bitcoin as a form of savings then you should know that savings is a life time goal and not just a few years goal hence if you consider bitcoin investment as your savings then you will probably deep hands into your savings to save yourself in days you need urgent money, hence making bitcoin investment you can consider it a life time savings that you would keep stacking up till a very large number of years, however at the same time, before you go for the goal of bitcoin as life time investment you should also make sure you have some kind of emergency funds or reserve funds to keep you going on days that might feel tempting to deep hands into your bitcoin investment.
If we consider investing in Bitcoin as a matter of whether the investment will be made continuously or whether this Bitcoin investment can be held for a long time, I think Bitcoin investment should be compared to that. There are many investors who do not trust keeping money in the bank, that is why they invest the remaining money in Bitcoin excluding their expenses and they consider this investment as savings. Although savings and investment are two different things, but if you think of savings as investing in Bitcoin continuously, then there is nothing wrong with considering investment as savings.
In the second line, you have highlighted another important point, which is to form an emergency fund to make investments continuously. An investor knows how important an emergency fund is for investment, many times when the need for money arises, the amount of money that an investor used to invest continuously is not invested by the investor, which results in investors becoming erratic in their investments. But if there is an emergency fund at that time, then even if the economic situation is bad, the investment will be continuous. Basically, those who are very serious about their investments are usually the ones who think of forming an emergency fund.