I can't say I rode in -40 but in NJ I rode in below freezing weather, ice and snow enough times to never want to do it again, except for fun ride on a mountain bike on a sunny day.

I used to commute 20kms each way to work in 2 top layers (one jersey and a thick fleecy jersey thingy), a gore-tex jacket, long tights, wool socks, gore-tex socks, booties, big thick ski gloves where you can't feel a thing because they are so thick and your fingers still freeze. Even had gore-tex pants for some really bad days.

Hardest part was the ice cream headache when starting out, felt like your head was going to cave in until about 10 minutes in to the ride.

I have pics of our cyclo-cross races in full snow, about 20 degrees F and a freezing wind blowing, insane but fun. We put on a race where frozen over puddles had to be broken through by the lead riders, awesome to watch !!

makes winter here look positively balmy