I've got that off-season ennui too!
By the way Cathryn, I was in Palermo and western Sicily for work reasons for a week in late Feb and it was CHILLY! The locals said it was unusually cold, but it rarely got above 7 or 8 degrees C, and up in the mountains (actually Sicily is pretty much ALL mountains) it was about 2 degrees. So I don't think it'll be shorts weather for you there during winter time.
However, I cannot sing Sicily's praises enough. The people are amazingly generous, the scenery spettacolare and the food out of this world. Mamma mia.