Your ADULT birds are just fine in your climate temps. The question arise, when hatching small ones during cold weather. Survival starts to be the issue, during COLD. I would avoid hatching out baby pigeons until SPRING. If they do lay eggs,,, you can replace those with fakes.
The other question,,, If they are High flyers,, Is the process of home-setting them to your loft. That means, being able to let them Loft Fly, and have them return home. It is a different challenge with different breeds. Homing adult pigeons, being the more difficult ones to homeset.