Most days I can get by with the rubber mechanics gloves above. I carry a pair of oversized mittens (Jokatherm or old rag wool choppers) when I am on the snowmobile. If it is really cold I have a new electric hand warmer I keep in my pocket. It was a 10000 mAH one so it lasted all day on low, which was plenty in a pocket.
I also got a pair of Cabelas dipped knit ice fishing gloves- they got so stiff in the cold I could barely get them back on, and they were so tight my hands got cold fast. They only had 1 size, so I guess I will give them to someone with smaller hands.