Jezz! What a bunch of hot house flowers...except 1nceptor and liquorlad and Leebo (maybe a couple of others)!
Frankly if I used 40°F as a cutoff, I'd ride maybe 3 months of the year. If I used 60°F as a cutoff, I'd ride (maybe) one month out of the year. Denver starts most mornings chilly.
-5°F is the about the lowest I've gone. I don't like to ride that cold because it more hassle than anything else but I
can ride that cold. Below about 20°F is where I start to whine enough to not enjoy riding.
You fair weather riders need to, as they say over in Road, HTFU!