I suggest choosing a shorter route that won't be intimidating to those who are already skeptical of cool weather riding, such as Lake Farm County Park right off the Capital City Trail. Hopefully, the ride will be proof enough that biking can be comfortable outside of the "biking season." It's common for newbies to show up overdressed and then quickly shed layers not long into the ride. Even at a conversational pace it's easy to warm up on a late autumn day. Maybe they will no longer think you are some sort of thick skinned mutant or plain crazy for biking without a jacket in 40 degrees.
After the vindication of a pleasant ride, it's time for a picnic. Mulled wine, hot soup, a baguette, and baked apples ought to keep your bike posse happy.