Moving from IB to Corporate Strategy - case interview prep?

My history first: -First applied to strategy/mgmt consulting in undergrad; never had any luck with case interviews -1.5 years at a lesser known investment bank -1.5 years at better IB

Now, I know why I want to move to corporate strategy, and in my mind, this presents an enormous opportunity to me. However, I've been told that it will consist of several rounds of case interviews, which I have never been very successful with. Read all the prep materials from LOMS/CiP, have read dozens of cases, feel like I have the frameworks down, but nothing. I haven't gotten the chance to actually practice a case, since I have no one to practice with - which I know is to my detriment, as that's where the real benefit comes in.

So my questions are: -How difficult can I expect a corp strategy case interview to be? A very general question, admittedly, but I'm guessing that they'll be a step up from, say, the stuff found in CiP. They say the interviews will be around an hour long, which is certainly longer than any other case I've done. Looking at the team members of the place I'm interviewing at, the "prestige" level is some high (MBB), some mid (PwC, etc), and some low (lesser known consulting shops), if that means anything. -How do I practice a lot, very quickly? Is there somewhere I can, for instance, buy time with a consultant on the phone for practice? Is there a repository of CS-caliber cases, as everything I've seen has been for undergrad?