I love my 40° Incubator and I'm thinking about getting something for colder weather. Even my 40° + 2oz overfill really takes up a lot of space in my pack, so I was wondering...how in the heck does a 0° pack? It just seems like it would fill the entire pack!

If anyone can compare the two or even all three Incubators that would be great.

I'm really tempted to try a 20° Phoenix, but anything other than FULL LENGTH scares my feet!