Good explanation Shy. Your -10º analogy is generally correct, but the water has been known to stay in a supercooled state down to -25º.
The problem with icing is that it there we do not have a substantial body of knowledge on the subject. There are so many factors involved in its formation and accumulation, that accurately predicting its effect on a given flight regime is impossible. Something like predicting the weather....we know the general rules, but the complexity of the system defies our ability to accurately and precisely predict it.
As you said, stay out of it. Period.