I'm not sure what the furthest I've ever gone without stopping is, but I know that I have done a few 200 mile rides without stopping. Those were done in the winter (no snow here, just 40F rain) when I drank very little due to the cool temperature and thus didn't need a natural break. As I get older, the time between bladder calls seems to be decreasing even faster than my average speed, so I doubt if I will ever do another double without stopping again.