Are you wanting to keep your hands warm while being mobile or while being idle? Those are two totally different things. Hunting location also makes a significant difference.
Take the following with a grain of salt. What is cold for me may very well be a "nice spring day" for someone who lives in North Dakota.
If you are active, then most any light(er) glove will work. The Krypton has worked well for me in that regard. It is also decent down to the 40s-50s when sitting idle. The older model Cadog is too warm to wear while active but may get you to the 30s if sitting idle; the 1st generation Cadogs were even worse. The older model Aegis is far too warm to wear while active but may get you to the 10s-20s if sitting idle. Wore the Aegis last November in NE while hunting whitetail. One day it was 0-10* in the morning and my hands hurt from the cold. For me, Kryptek does not make a true cold weather glove for glassing before dawn to after dusk.
Lesson learned. If it is cold and I'm glassing, I'm wearing my Kuiu Super Down mittens (with or without a liner glove). If I am mobile, then I'll wear my elk skin gloves or a lighter pair of gloves and call it good. If I archery hunted, then I'd wear light gloves with a muff with hand warmers inside.