Extra cost to return to HK one day early, worth it?

I currently hold a Helsinki -> Amsterdam ticket with one airline, and an Amsterdam -> HK ticket with another airline. My current tickets allow me a 17-hour overnight layover in Amsterdam, with a cancelable airport hotel booked.
I have to go directly to a camp just a few hours after the flight lands. If I am asked to help out with something, I have the option of changing my flights to depart Helsinki in the morning instead of the evening, and I will have a 3.5 hour layover in Amsterdam to catch my next flight (but I need to go through immigration twice), allowing me to land an extra 24 hours early. But I need to pay at least €120 to swap flights.

Is this layover time enough for me? Is it worth it to swap flights, or I will be better off declining all requests to help out during the camp and stick to my original flights?