I have a cold compost pile that I tend to. I have been dealing with a number of diseases, predominately related to my tomato plants. I just want to be sure that the spores of theses diseases won't survive the wisconsin winter (Zone 5B) and encourage disease next year. For example, as far as I know, powdery mildew makes its way north every year (migrating like birds and bugs). So I wouldn't worry about adding powdery mildew infected plants into my compost, as the spores will die during the winter. I know hot composting could also alleviate some of my worries, but that isn't happening.
Thoughts on this subject are apprecaited. I've found a number of different viewpoints on this. But it seems the big questions are A. If the spores survive the winter and B. If they do survive the winter, how much greater is the probability that your plants will be infected by the compost and not just their arrival with the warmer air.