Honestly, I don't think you can answer that question without knowing a few things that factor into it:

1. How competitive is the program? When would you normally start designing? Are you picking music and getting drill written to it, or is it more involved than that?

2. How likely or unlikely is there to be a big exodus when a new director comes in? If yes, this could mean picking a much more manageable show to ease the load for the next guy.

3. How soon will the new director be in place? If early enough, maybe they can have input in the show.

From experience, I knew with certainty by spring break that I was taking a job at a fairly competitive small school. The outgoing director and I worked closely to find a show that was going to be a really good fit with the students. (It worked out pretty well.)

As someone who designs and arranges music (and teaches full-time), I would err on the side of having the show picked out and ready for the next director.