I went on a 20 mile ride on Saturday and my rides begin with a long 2 mile downhill no matter which way I choose. I get what your saying about the cold. The wind (low 40's for me) had me wincing from the cold draughting through the helmet vents on Saturday. However, once I hit the base of the hill and started riding the straights I soon warmed up. I also got all toasty when I had to climb 2 miles UP the hill to get home. By the time I got home I was dripping with sweat. For me, the sweat is the whole point of our odysseys.
If I hibernate till Spring, I just dont know if I can get the habit going again - I choose to ride no matter what the weather and not take the chance. Your going to get wet/cold (rain or sweat) no matter what your wearing so dont waste the money or time on worrying about gear.

Keep it simple - dont over-think - just spin the pedals - its the only answer and its really not rocket science

Keep riding