I don't know if it it's possible, but it would be really nice to have an easy way to reorder answer chapters. As in like the order in which the choices of following chapter appear.
If you haven't published yet, you can simply create new chapters in the order you want them, copy-and-paste your content, and then delete the initial drafts. In fact, depending on how branched your threads get, you could conceivably do this even with published chapters ... just copy all the content to a Google doc, then edit each of the branches to change what's in them to the order you prefer. On the other hand, if the threads are sprawling or if there are other circumstances, all of this is impossible -- in which case I'll join you in wishing that it was easy to re-arrange threads and branches!