Pose lots of unanswered questions in a PhD thesis chapter?
The posing of "open" questions is quite common in doctoral dissertations, usually in the final "conclusions and outlook" section.

However, your situation is a bit different, in that you have an actual project that is designed to address these questions, but the study is too long for you to wait to include the results in your PhD thesis. Given this, I would basically do what you've said: introduce the basics of the case study you've designed, what it's designed to do, and so on. You just won't be able to present the actual results of the experiments. If this is clearly communicated to your committee by both you and your advisor, then this shouldn't be a major problem.