This is where having a second PC you can devote souly to rendering comes in handy. Unfortunately, since I lack that, I just don't start an animation render until last thing before I go to bed, and let the thing run all night. I've ran an animation render for three days straight once- I can say from experience that I don't recommend using dynamic hair in lengthy animations unless there's no alternative. Stick with P4 hair and magnets if there's any chance to get the same effect that way.