I do not really see much challenge here because the essence of making investment is to be able to solve personal problems from the proceeds of such investments and we in this sphere chose Bitcoin so it will not be bad seeing that someone is able to get married and raise a family through the part of the proceeds of his Bitcoin investment. What I see that is bad is selling off ones entire Bitcoin to use the money for marriage ceremony. This is bad because marriage bring additional responsibilities so having investment in Bitcoin will be a wonderful leverage.
Like you rightly said, marriage should be planned properly in such a way that it does not hinder the investment even though it might require adjustment of the DCA amount by pushing more funds from the DCA money to the reserve funds to accommodate the marriage and family requirement. As long as the DCA method is running smoothly even with reduced capital, I feel it is fine.
I don't know how it may sound if I suggest that: we should all get at least two source of income. An exception to this idea is when you have a single buoyant source of income with good income, and could probably cover so many expenses including your investment funds for a period of time. My reason for suggesting this idea is because, having a single source of income that is not buoyant could possibly could possibly have effects in our long run investment. Take the marriage and raising of family as example, that is a complete life style that comes with a lot of responsibilities. Your monthly budget is multiplied, as they are more stomach to be feed. But when you happen to have multiple source of income, the financial pressure would be absorbed a little, which might possibly not change your investment plan in any way (whether DCA or any other).
Just like I said earlier, having multiple sources of income is advisable, except your only source of income is buoyant enough. Not sure if buoyant is the right word, but I hope we all understand what am trying to say.
And again, having multiple sources of income can be quite difficult, especially in countries were unemployment rate is very high. But I think we can all give it a try by looking for, or creating for ourselves. But we must never introduce greed, so we won't be worn out at an early age.