I am currently working on a hard science fiction apocalyptic novel which I'm trying to reign in at 81,000 words. Unfortunately, that doesn't leave me a whole lot of room to tell the story. The story I want to tell could comfortably fit into 108,000 words, but I'm told that publishers won't consider a piece that large from a first-time author. Are there any exceptions? How does one go about securing such an exception?