Find some other entrants to chat with to while away the long hours in the saddle. Also, having a companion or two can be of help if you have a repair to do, or to keep from becoming lost. It is also best to be in a group after sundown. When cycling at night, cars' headlights will spot a small group much better than a solo rider. Make sure you have lots of reflective stuff stuck to your bike and on your helmet and clothing.
White jerseys show up well also.
On a quiet country road nocturnal cycling can be a wonderful experience, especially if there is a full moon up. It is exactly these sorts of sublime moments that keep so many randonneurs and randonneuses coming back for more year after year. If, however, all this is feeling too much like a chore, try eating more since you're probably bonking. Or, put on another layer of clothes if you're becoming too cold. Perhaps you're in need of some company too.