So much of your coldest riding is between 30°F and 40°F. Rain?
I picked up a pair of Specialized Defroster boots, but my bony ankles don't like them.
As mentioned, the Shimano MW-02, and I presume the revised MW-81 are extremely comfortable... I don't get real cold, but I think I've had them out to 20°F or so (-5°C). I don't know if my feet notice the cold a lot (as long as they aren't frozen), but I could wear the boots from freezing up until fairly warm weather (20°C or so?)