Not gloves - mittens! I use "chopper mitts" (deerskin wood chopping mittens with liner mittens inside. Been using that combo for 50 years. It works. 40 years ago I rode the 12 miles to work one week with -5F at the house every morning when I left. Now, at 65 yo, my hands would not be able to take that combo for that ride. I would probably re-install my fairing. That would allow those mitts easily. (The rest of my body is having the same issues. I'm also having to turn up the house heat and/or wear thermals just to get by. As they say, the only thing worse than getting old is the alternative.)

But to get back to those mittens - chopper mitts do rule! Buy the largest size you can get, I get XXL. The leather is so soft and grippy that,while you cannot use some of your split finger summer positions, other positions open up that would be too hard with the slippage in the summer. I can't tell you anything about operating brifters with those mitts as I have never run them. DTs are easy. Most of my winter riding is done on fix gears anyway. Another huge plus of the choppers is that taking them on and off is easy. So easy you can pull one riding to reach into a pocket, then pull it back on. And with you fingers together, they will warm back up after being seriously cold after you repair a flat.

Google "chopper mitts". As far as I know, all the hits will be for the same mitts; at radically different prices. Dress the leather once a year with Snowseal and they will last a long time. REI has some good inner mitts.

Ben