I'm with all the folks above that recommend riding junkers in winter. I can't fathom the idea of riding a good machine in the winter salt and sand.
Dress just like you were going cross country skiing.
I agree that it is the wind that intensifies the cold. Cover everything up with wind-breaking fabric shell. I find that a silk balaklava is one of the most key ingredients to comfortable winter biking.
Gaitors for your calves also help tremendously.
Stay on the road, my friend. Don't let the winter stop you.