Wow... i'm responding late... but hey - here I go.... just in case someone comes along later for this.
Answer is: ADR. Do what the major features do for a profound amount of their dialogue - just re-record it later.
Let me tell you my favorite and totally unorthodox way of recording as ADR.
I do it at a location like (not EXACT) but somethng like the real location. I record it with the same mic AND I put it only as close up to the actor as would be somewhat feasible in the shot... meaning I don't put it 1 foot away from their mouth.... I give it space. Then... I play back their lines in short phrases and without any beeps or boops, and without watching their performance... they just say it back how they said it. They can close their eyes, go whereever they want to in their heads... or relive the scene a little.
Then.. I just edit it in. And it WORKS! Amazingly well too. And you don't have to be a godly mixer to make the fake ADR sound convincing. And it's cheap and easy to do.
My 2 cents.