I've got a fever...
On your deathbed, you won't wish that you'd spent more time at the office. But you will wish that you'd spent more time running. Because if you had, you wouldn't be on your deathbed.
I will say this about winter training. It sucks, but in addition to the physical benefits of the miles, you reap huge benefits from it psychologically. I always felt mentally tough after putting in a lot of miles in crappy, snowy weather. I convinced myself that my competition wasn't out there, and I was.