So I am a DM and I have an award flight in a few days. I just found out I may not be able to leave that day. I can redeposit and rebook no problem without a fee. But my question is I may be able to take the original flight. Potentially could find out right about the time the flight leaves. How close to the flight can I cancel? Could I be checked in and at the airport then cancel?

And the reason I don't want to change now is because my sister and nephew are also booked on the flight I would like to go with them if possible, if not they are going to keep the original flights and only I would change.