You are spot on. I think the worst i have experienced was wiring up a shipping container which was being turned into a water treatment plant. It was around this time and around -5C in the container. I had , i think 5 layers on core (all my snowboarding gear) and 2 layers on the legs, 2 layers on the feet. Was holidaying in sweden on a lake, it was -40C - wow that was cold, again you really do have to dress for the occasion.. lol
Simply put if you are getting cold hands and feet, you body is too cold and the blood vessels have closed off blood to the hands and feet to keep the vital organs warm.
No amount of technology will help, TBH, cos the blood has stopped flowing..
Its not really that cold atm, so worth trying to layer up just to see if it works for you....
FWIW, i use thermal
vest, regular
shirt, thin fleece, thicker fleece, big quilted jacket, russian hat. No gloves required... lol