When I lived in Canada (Winnipeg), I commuted down to -40C/F and cycled longer distances down to about -32C or so. I don't know if it is still up on my website (I'm slowly restructuring my website) but my coldest century (100 miles in one day) started at -32C and got up to a nice balmy -25C or so.

Now I live in Australia and find myself complaining when the temperature gets close to 0C.