Dennis, take a good look at the northern half of Italy. From Florence or Bologna north to a line that goes through Venice and Milan to the west. If you go farther north most of the time you will love the climate but winters in the Dolomites and north of Lake Como, Lago de Garda, and Maaggiore can be cold and snowy.
Look carefully at the Provinces of Emilia-Romagna, Veneto, Lombardia, and Piemonte. Italy is so mountainous that some parts of any mountanous province can be a lot colder but I think those four provinces are a good starting place.
Jess's answer is a good one and considering that Italy taxes by "residency" or those who are there more than 183 days a year, her Idea of going back and forth may be excellent for you!
Chip Stites, Italy Correspondent, International Living Magazine.