Cold as a...
Part of it is the 6000 mile goal I set for myself. If I slack now, I'll have to ride doubly hard later on. Part of it was that I skipped todays this week already. I had to get the miles in to make my weekly goal of 120miles. And I did! I made 130 miles for the week. Yay, me!
The other part is just the fun of telling people "Oh yeah, I rode 30 miles in the freezing cold." Something about the surprise that it generates makes it more fun. I won't have the opportunity to provoke such reactions in the summer.
But I think 30 miles is my limit. It takes me around 2 hours to ride that far and by the time I get back home, my toes are numb -- even after I put on extra socks.