I finally found gloves I can use after years of searching. I have a huge pile of gloves that work up to a point and then my hands get cold.
These Gordini mittens are paper thin, and I thought, these can't possibly work. And they do. They are so thin, I can pick up a quarter. Plus they have that inductance-passing feature that I can use a smartphone with the mittens on! When it gets very cold, I put
these cheap gloves on under the mittens, and that works. I rarely need to. I rode over an hour each way yesterday without the gloves. My hands get cool but not cold. The mittens have so much room that I can make a fist when it's safe to do so, and that warms my hand back up.