We just got back from two weeks in Italy - Rome, Compania and Tuscany. There were some people, but the only real crowds were in the piazzas in Rome on New Year’s Day. The security wait for St. Peter’s on Jan 2 at 11:00 AM was only an hour, shorter than average. The Archaeological Museum in Naples was so empty it was creepy. Weather was good, highs 55-60 F each day and only a little bit of rain.
While we couldn’t enjoy the beach or the boat trip around Capri, this was the time window we had and everything else was great. I definitely recommend Italy as an off-season destination this time of year!