I'm attempting to execute the "Damsel in Distress who Rescues Herself" trope. Which, of course, begs the question, what is H doing during this time period.
Best option I can see is that H is blissfully unaware she's in distress. Maybe she sends a messenger but he's off fighting a villain, and the message doesn't get delivered etc.
Another option... maybe he's aware but is too late. Not sure how that works as I don't think the hero's allowed to be late.
Note that at this time, the characters are already in love. The rescue is not pivotal to them getting together. The danger exists to help prepare the MC to assist in the final battle.
So my question is: To what extent does the average reader accept that a hero can't arrive in time? Is unaware the better choice? I can put him so far away there's no prayer of him arriving in time. Too obvious? It's great if he can arrive "just in time" that she's gotten out of the danger a split second before. Campy?