As to your question about how hot is too hot, one thing you may want to think about. Riding in the snow throws the white stuff up and onto the hot parts of your engine. This causes steam, which actually feels hotter then the same temperature air. It will pull the heat out of the engine and transfer it to the air, more than just air will, hence why they make liquid cooled motors. Have you noticed the bike running hot at any other time, other then in the snow? You may not have a problem at all, just feels like it. It is better to be cautious with the bike though, lot cheaper to fix stuff that isn't shrapnel. But this is something you may want to check