I think if I had to choose just one plant that would or might bloom in the winter time, it would be Hamamelis - Witch Hazel. And if I had to pick just one of those, it would definitely be 'Rochester'. It is large, reliable and early. Ours is on the bank above the upper pond and gets lots of sun. It is always the earliest of them to bloom, usually by late December and stays in bloom until the warm weather comes in the spring. It is also one of the most fragrant out of the probably 20 different ones we grow. I continually cut small branches to bring in the house (you don't need a very big piece to scent the whole room) and enjoy it all winter.
My walk was a quick one, just up to see the plant and back in. Despite the sun and a temperature of 40 degrees in the afternoon, it still feels like winter out there - not like the 12 degrees it was first thing in the morning, but we are pretty much done with spring for awhile, which is as it should be. The plants all need their winter break and so do I.