I'd go with a vented winter sports helmet or a bike freeride helmet. They have more clearance for goggles and they come down more in the back to keep the back of your head warm. They have only just enough venting to let moisture escape and are much warmer than well ventilated bike helmets. Plus they are designed for even higher impact speeds. Generally you won't need anything more than one thin hat or balaclava under them since they are a lot warmer than a bike helmet and can be found cheaper too.
It is easier to size them because you don't have to wear as much on your head with them to stay warm.