Originally Posted by bikester62 What do others do?...
I wear amber, light gray or clear cycling glasses but not ski goggles when riding in the cold. As you've found ski goggles just can't breathe well enough and they'll fog if you're exercising hard. Even when back country skiing we remove goggles after a descent and put them away while climbing back up or they'll get hopelessly fogged as we generate more heat and sweat more during the climb. I wouldn't expect ski goggles to be able to keep up with the kind of heat we're pumping out while riding bikes. The only place I've been able to work relatively hard while wearing goggles without fogging them has been on high altitude mountaineering trips and then only when the temps are well below freezing as in the -30 to -40 degree farenheit range.
They do make some ski goggles with built in fans to help them vent but I've never tried these. I've done some riding and a lot of winter sports like cross country ski racing at temps much colder than you're talking about and a decent set of amber sunglasses typically works great. They can still sometimes fog when I stop moving but they'll clear up real fast if I just move them a little further from my face and get back in motion.
I wear something like these in the winter: http://www.performancebike.com/bikes/Product_10052_10551_1024720_-1_400902_400902_400902