You really want to have 2 or 3 cams. It just makes life so much easier. If you shorten them right up, you will have a hell of a time putting them on in less than perfect conditions. Without cams you will need to use bungies, but then you will always be losing bungies on the trail.
Anyway, I don't understand the hate for chains. When it is icey, life is so much easier and safer. They are quick and easy put on, should be less than 2 minutes and don't slow you down off road. They cost less than the price of a tire for a pair.