If I want to stay warm in winter, I stay inside. If I want to fish, I face the fact I'm going to be cold.
Neoprene waders go a looooong way to warmth (although I can't stand wearing them). I good waterproof jacket on top is key. And like they always tell you -- layers, layers, layers. Some day I'll get some fancy neoprene gloves, but for now, I'll stick with my super-thick wool fingerless, which are better than nothing, and still allow me to fish.
For the most part, I've gotten lazier these days, and try to mostly go with my friend in his driftboat, with the heater fired up.
And also... booze. Booze keeps you warm, and if it doesn't, it makes you care less about the cold.