It is doable if you tilt the conditions in your favour
1. get a very reliable bike, something like an Alfine 11 hub gear with drop bars
2. fit aerobars
3. you pick the course. I suggest getting a friend to drive you to the highest point possible, and then cycle downhill with the wind behind you.
4. wear good bib shorts, an "aero" cycling jersey, and other good kit.
5. if possible have a cycling partner to lead you so you can tuck in behind