I've started considering the possibility of riding a double century. Any suggestions for someone transitioning from riding centuries to riding a double century? Since September, I've done six century rides, with the longest being 125 miles long and the steepest having over 10,000 feet of climbing. There was a one month period where I rode one double metric, three centuries, and one metric. I basically feel like I can ride a century whenever I want right now with no special preparation.
I intend for my first double to be relatively flat, so climbing ability shouldn't be an issue. But I figure working up to the sheer distance and getting used to riding at night will be necessary. And I figure I'll need to start eating and drinking a bit more since I currently run a mild nutritional deficit that allows me to ride a century comfortably, but leaves me really hungry when I'm done. Is there other stuff I should be working on and preparing for? Any other advice for preparing for a double?