The majority of travellers in Italy are Italians. The majority of the rest are other Europeans. Every day there are more than ten flights from Barcelona to Rome. A similar number from Madrid,London, Paris, Berlin etc. All full. Plus the people who take the train or just drive across the border.

October you'll run into school bus tours from France or other countries.

I think before Covid the number of tourists from China had more or less caught up to the number of Americans.

Well, I must say I think it depends on one's interests! There are MANY fascinating things to see and experience in Italy, including many places that aren't in the north.

I've skipped posts so sorry if this repeats but in the way back when, my DH and I could only travel in March, we made certain we were there on and around the 17th on our anniversary. In smaller areas, not all local tours had started but that was the only problem. Some boats had winter hours....check ahead. The only time we forgot thermal underwear was when we needed it, otherwise, we layered and were fine. We visited 6 or 7 times.

Museums were open. Rather than tourists, the crowds were school kids but they moved quickly. We weren't hikers so the weather wasn't a huge factor.

We've visited Italy in spring and fall, and our favorite trip was in 2018 from late September through early October. We visited Milan, Bologna (with day trips to Ravenna and Padua0, and then hit Piemonte (my favorite) hill towns (stayed in La Morra) in early October for the beginning of white truffle season. I can still taste the pasta. We also hit Turin and Orta San Giulio on our three week trip. Hope to make it back in next couple of years. (Trip report with photos below). Have a great trip.

https://travelswithmaitaitom.com/italy-2018/