I use a Sugoi helmet cover and rain shell. It has side-zip vents you can open to reduce the green house effect. I just ride in my jeans, and deal with the wetness. At work, I hang them up and they're dry by the time I go home. (I only have a 3.1 mile commute.) I'd like to get some water-resistant pants from REI, but they don't make them in fat girl size.