It won't solve your problem on its own, but you may find that making sure your feet (as well as your shoes and overshoes) are nice and warm before you leave the house makes a world of difference, and take longer to get cold. Cold extremities cause blood vessels to constrict. This in turn decreases bloodflow, which prevents said extremeties from ever warming up, even if the rest of you feels warm. Warm extremities cause blood vessels to open, and more blood means more heat in those areas slowing down the cooling in the process.
Having a nice hot shower right before you stick your gear on (rather than before breakfast for example) also helps.
If my hands are cold after walking the dog in the morning, but before commuting, I run them under the hot tap for about 30 seconds before I leave. It makes the difference between them staying warm for the entire journey, and starting cold and never warming up. If the weather is likely to be particularly cold, I will often stick my gloves on the radiators, rather than leaving them outside in the garage too. Same for shoes - they can go in the airing cupboard the night before.