I have ridden long rides with guys that are really fast. They are usually good about riding with me for part of the time and riding faster for part of the time. (Ha - they probably liked the break they got.) If you can, it might be good to visit them or have them visit you a few times in the preceding year to build some camaraderie. Try to get one or two rides in together beforehand, even if they are short.

In the meantime, build that strength! Ride lots of hills! Some women are able to build strength and speed and keep up with men pretty well. (Not me, but some!) You could be one of them.