If you can I'd say move the two GoT subforums after the characters one and leave those two spots open for the final books (if you can rename the subforums threads). We can start talking about theories and guessing of what might be to come.
Another subforum can also be about pretty much just hypothesis and mysteries and prohpecies within the stories (i.e. jon snow's mother, so-n-so's schemes and ultimate agenda, so-n-so's dreams, mags prophecy, and a person's ultimate fate whether they are alive or dead, etc..)
Might I also suggest a rule posted about not putting spoilers in your thread title.
Dunk and Egg Tales subforum?