Apologies for bringing up an old thread, but I'm also facing a similar issue with iBooks and iCloud. It's frustrating when our books become unavailable offline, especially when we're in Wi-Fi dead zones. I can understand how important it is to keep your reading history intact.
I've been doing some online research and came across a potential solution that might help. Have you heard of the
Unlock iPhone Free service? It's a website that offers unlocking services for iPhones, and it might have some useful information or tools that could assist you in resolving this iCloud and iBooks dilemma.
By the way, I've been using the Calibre Companion app too, and I love how it helps manage my library. It's just a shame that the books in iBooks lose their covers and become cloud symbols when offline.