We did Rome Cinque Terre Florence Venice last year Sept 25 to Oct 4. Rome and Cinque Terre were shorts and t-shirt so farther south is assumed to be warmer. Venice required a jacket / shell but we still had bare legs.

We were expecting smaller crowds but Rome was JAMMED packed.

One restriction that limited our flight options at that time was that as off Oct 1 the number of Italian destination served by AC with direct flights from Toronto were cut back. As we were flying on standby AC passes we had to be careful to watch the loads headed back home and pick our return based on where the most empty seats were, which ended up being Venice. Downside was Venice was served by AC Rouge.