Hi,
I was one time in december for cycling in Sicily. It was fine to cycle, although the days are rather short. My route was from Palermo over Segesta to Erice (nice old town on the mountain)-Trapani, than to Selinunt and Gela and at the end I took the train to Catania and climbed the Etna (road to th rifugio sapienza) and over windpressed snow to the top of the mountain.
By the way, if you want to relax a bit from cycling, the eolian islands are rather comfortable. The months of january, february and december are realy good if you like it anticyclic, almost no tourists and therefore less infrastructure. But it can even snow down to the sealevel.