Seems like the older I get, the more problems I have with cold feet. Even in modest weather like 25-30 degrees. I've tried toe warmers, battery operated heated insoles, liner socks, every type of outer sock, and many cold weather boots. Yes, I've heard the old saying if your feet are cold, cover your head. Believe me, I'm insulated to the gills but still have chilly feet due to some circulation issues.
About a month ago I ordered a pair of the 1600 gram Thorogood FD Infinity Series rubber boots. I'm impressed with the quality of the boots and how warm they keep my feet. I recently had a chance to hunt in 20 degree weather. I was comfortable for more than 4 hours in my ground blind. If anything, my toes actually felt a bit hot.
Amazing how still one can sit when all parts of ones body are comfortable. If you've struggled with cold feet, you might give the FD Infinity Series a try. They come in several different insulation weights and all have a lining of 'Solarcore'--an aerogel insulating material developed by NASA, I think.