Sometimes charity rides allow people who have raised a certain amount of money ahead of time to start ahead of the pack, and that's a great way to avoid the throng. Just time your start so you are 10-15 minutes ahead of the main pack, but behind the early starters. You'll start to almost empty roads, and it will be a lot more fun. It also means that the rest stations have not yet had a chance to run out of power bars or whatever free food they are offering.