I found several days of pretty and varied riding in September in northeast Italy -- see map + photos.
I haven't seen this region talked about much in English-language forums, but it has a lot to offer for road bicycling . . .
Riding which was some of the best of its kind I've found in Europe or N.A.:
ridges of Langhe: for big views out to both sides [ report | photos ]
around Gran Paradiso: grand adventure with variety of mountain and valley, hiking and riding [ report ] - (as also was the Grand Ferret / Gran San Bernardo loop on previous trip)
Colle del Nivolet: for pretty lakes under snowy mountains [ photos ]
Elva gorge: wild exciting spectacular descent [ report ]
Other riding on this trip I'd be glad to do again:
Colle dell'Agnello pass, third highest in Europe [ report | photos ]
some of the gentle riding in farmland in Torino + Cuneo regions
On previous trips I also much liked:
Colle del Gran San Bernardo + Col du Grand Ferret mountain loop [ photos ]
Col du Montgenevre + Col d'Echelle loop (near Bardonecchia + Cesana Torinese)
Moncenisio / Mont Cenis mountain pass + lake from Susa
Comparing with other regions, I would definitely prefer to do more riding in Piemonte (Piedmont) than Tuscany, but for mountain passes I think so far Südtirol / Alto Adige + northern Veneto still have the edge -- unless you want access to views with more snow. And I think I'm liking the farm-country riding in the Rhone-Alpes region of France (e.g. along the Isere river around Montmélian) a little better because I found more animals to see along the roads -- but if it's vineyards and nut trees you prefer, Langhe has more.
My approach: Just like home in USA I got myself and my bike to the start of each day's riding by driving my (rental) car.