The only theme that’s doing anything close is Chapters by WooThemes. It was designed for authors who want to publish books online. You can follow by chapters in this theme the same way I’d like to follow days in your journey.
And speaking of which, haven’t you been reading a lot of travel blogs in preparation for your trip? That’s not as easy as it could be either, right? I’ve yet to find an app that will let me rip the whole archives of a website, in chronological order, and save it to my Kindle. Instapaper and Readlists are close in that they allow you to save articles in .mobi or .epub format, but it doesn’t have the functionality to rip a whole site. I’d pay for an app like this and I know I’m not alone. PHP alone wouldn’t be all that’s required for this type of app but you could charge a monthly fee for the service, allowing your marketing efforts to be reduced significantly and your runway to be infinite.