Since every choir director I know lives somewhere on the spectrum of workaholism, I have a recommendation:
Take a listen to Adam Grant’s WorkLife Podcast (sponsored by TED). In particular this episode, entitled When Work Takes Over Your Life. Maybe while you’re catching up on email or filing choral octavos.
The entire first season of WorkLife is great, but this one is especially relevant to choral musicians, with its emphasis on what he calls “Engaged Workaholics” – that is, workaholics who are inspired and excited by the work they do.