The spool running out does not mean the work was almost finished.

Running out of something tells you about supply, not about progress. A thread ending, a budget emptying, or a deadline arriving describes the resource and says nothing about how much of the work is done, though it feels like a signal because it arrives with such finality. People often treat exhaustion as evidence that they must be nearly there. Those are separate measurements, and only one of them is about the work.

Check where you actually are against the task rather than against what is left in the tin. If the two do not match, plan for the gap now instead of discovering it at the end.