Unfortunately not. Casualty of the move. Those big threads we probably will need to just lock (no future posts), and continue them anew. New multi-page threads will work as expected (IE, normally), but there really isn't a way for those large multi-page threads to be broken up (completely different way that the new software handles pages & URLS).
It sucks.. I wasn't happy about it either but I just don't really see an alternative.