Assisi - nights 4, 5, 6 Here is where I am looking at possible change.
It depends what you want to accomplish with your trip. Some people plan trips with the goal of "doing" a city and checking off boxes from a guidebook inventory of museums, castles, monuments, etc. (yes, sometimes I travel that way, too). You can "do" Assisi easily in two nights, even one if you hustle.
Assisi, however, is less a place to "do" than a place to "be". Whether or not you are Catholic, or of any particular faith, the tranquil, spiritual essence of Assisi is palpable and enchanting. That is especially true in the evening and early morning.
We spent five nights in Assisi a couple of years ago. We hated to leave, but we had to get on a train to "do" Rome before flying home. Our fondest memories of Assisi are of the people -- the clerk behind the counter at the tiny grocery store, and the friendly local customers who helped us decide on our selections. The cafe owner who proudly showed us the Roman-era foundation of her shop, visible in a glass-enclosed cutaway in the floor in the back room. The cheerful laundress who had our clothes washed, folded and ready right on time. (Did I mention none of the foregoing spoke word-one of English?) The silver-haired Franciscan friar smiling and laughing as he chatted away in Italian on his iPhone in the piazza in front of the Santa Maria degli Angeli cathedral. The smiling shopkeepers greeting each other in Piazza Comune as they walked to work early in the morning. We can't remember being in a place surrounded by so many happy -- joyful -- people. (Well, except maybe the old gypsy lady in the piazza of Santa Chiara, who when I declined to give her money, stormed off muttering, "Cattivo francese ...!")
When the daytrippers arrived, we moved toward the outskirts of town, away from the "sites". We walked up the hill to Rocca Maggiore, and contemplated how the view of the valley must have affected St. Francis a millenium ago. We sat in the tiny, sparse Church of San Stefano, and understood what our hotel owner had told us, that locals prefer to plan weddings in the humble setting of this stone church, rather than in the massive, opulent Basilica down the road. St. Francis would have approved.
And when night came, we stood at the rail of the rampart of San Francesco, overlooking the lights of the valley -- just the two of us and a couple of Franciscan friars, in silence. Maybe it was 20 minutes we were there, maybe an hour. Didn't matter.
Rick Steves talks of travelers becoming "temporary locals". There is no better place to do that than Assisi. If you decide on a shorter visit this time, scope it out and plan to come back. We do.