I think this is a psychological matter where your emotions and your alternative source of income flows have to determine your goals and as well your time of holding before taking a sells decision.
Investment plans is mainly determine by the nature of the investments solely influenced by the individual, you may be wanting to go on an investment plan for 5 years but the reasons for that would be limited to more than the years assigned for the investment, so for long term investment especially involving Bitcoin be rest assured of your decisions before executing the plans of investing.