Yes. apologies, in a rush to get ready for work so this will be quick...
1. Provide word counts rather than page counts. Page counts can vary, e.g. font size, gutter, margins, line spacing, A4 or paperback size. If, for example, it's in manuscript format (ie double line spacing) then that makes a helluva difference.
2. apologies if you know, but splitting a book in 2 isn't straightforward. If you split it in half then the traditional beginning-middle-end is gone, and you've just got a beginning and a bit of a middle, i.e. no climax at the end, no resolution. That's likely to put anyone off as a reader, because reading a book with no ending is not fun.
It can be done, of course, but it's unlikely to be a simple/quick process. Of course, your story may lend itself to being told in 2 parts with a bit of tweaking so it isn't necessarily a massive chore either.
A longer third volume isn't necessarily bad, but it kind of depends on the other books and their respective word counts (i.e. 10 times longer than volume 2 might not work).
