Swany
https://www.swanyamerica.com/gloves/mens/
Their gauntlet style gloves or mittens with chemical warmer pockets will be very warm. I prefer gloves over mittens for shifting and braking but that's my preference. Either way, with chemical warmers you won't have a problem.
The
X-Change is their most popular. They are very durable. Mine have lasted many years. If you don't want to mess around then the
X-Cell is probably their warmest. The
X-Alt 3in1 look nice too.
If these aren't enough then get electric heated gloves.
-Tim-