Depending on what the road conditions and if you desire to continue to ride through the winter (assuming you live in a colder state) I'd go with your first choice because of the disc brakes.
My town just had 10" of snow dumped om us last Saturday and that has put a damper on our group ride. I too was thinking of a cyclocross type bike, fatter tires and definitely the disc brakes but a speedier, lighter weight bike than my mt bike 29'er so I can keep up with the faster riders for the winter months. But after this last storm .. I am looking to a fat bike instead. I suspect we are in for a snowy winter and I don't want to be stuck inside on my trainer all winter. Last year we didn't get much snow, had rain instead .. but I see the writing on the wall
