The more important news first: the Oliver Purnell era is done at Clemson. He's headed to the sleeping giant of DePaul, a school I've always kind of liked and think he'll be able to do well at. It might seem a step backward, but DePaul has nearly unlimited potential: Catholic school with lots of money in a gigantic city that produces absurd basketball talent.
Purnell's Clemson teams were never a big threat to dominate the ACC or go deep in the conference, but he did very well at a school where basketball comes second. He might've plateaued there, but how much better could they do?
OP's efforts are extremely dramatic. Clemson is light years better than it was under Shyatt. Purnell has done a great job bringing in quality talent and getting players to utilize this athleticism well in transition. However, if OP cannot get some shooters and cannot get his teams to play better fundamental basketball, I fear Clemson may be at its highest level. Any upgrades in perimeter shooting, free throw shooting, and fundamental basketball and you should see this team at least as an annual Sweet 16 squad.
Certainly not an Al Skinner situation, where the fans will be happy he left, but he's a God in their eyes, either.
As for where they go, well, let's just pray it's not Brad Stevens. I haven't heard a lot of talk as to possible candidates, but I imagine Stevens would be a big one. The only question surrounding that is whether Clemson is a better program than Butler, and I'm not sure it is. That'll be an interesting job search to track, because, in my opinion, Clemson's stuck between a "semi-elite" status, like Maryland, and an "average" status, like Boston College.
Speaking of Boston College, they've found their man: Cornell HC Steve Donahue. Color me unimpressed with this one.
Boston College has little in the way of a fanbase and they're not especially known for their basketball prowess, so they're not going to be elite anytime soon. With that in mind, it's not a bad hire; I simply don't see a program transformation because of it. Donahue will right the ship and probably keep them afloat, but playing and recruiting in the Ivy League is a very different ball game than doing it in the ACC; in some respects easier, in other respects harder, in all respects different. It's an intriguing hire, that's for sure, but I'm not sure he's the perfect man for the job. We'll see.
Oh, the winds of change. How they are fickle.