Liz--You might really enjoy a sunrise ride. Believe me, you can acclimate to the cold. The first few cold weather rides are the worst, but with the right layers and chemical hand/foot warmers, you'll be fine. I love the light that time of the day, and you get to see a lot of wild life (raccoons, bunnies, foxes, and occasionally, a coyote for me!!). I often have the trail pretty much to myself for the first hour or two--nothing beats it. Have to admit that as much as I love the spring and warmer temps, I do not at all like the influx of "fair weather exercisers." Those of us who brave the winter cold should have emminent domain!!! LOL.
By the way, I sometimes fantasize about having a handlebar mounted super soaker with which I could blast the most idiotic of trail rules offenders. It helps me keep my sense of humor to imagine blasting them out of my way.