I'd alwasy turned my nose up at heated jackets for biking... but, hitting 50 last year, I decided to try one to make biking in the winter a little more enjoyable.
I bought a warmnsafe jacket and remote controller. Easy to setup and toasty warm. I rode into the city centre this morning, 1c, and was snug and warm.
I have half muffs, barkbusters, which deflect most of the wind and allow the heat from the grips to be felt. A balaclava under the helmet and I can ride, comfortably, in chilly weather.