17 days in Northern Italy (late Sept–Oct): hiking-focused itinerary — feedback on route & nights division?

We're going 28.9 to 15.10, and we want to understand if we're doing the most optimal/fun route.

The plan so far:

• 2 nights in Milano
• 2 nights in Como
• 6-7 nights in the hiking areas — we both like hikes, so we want to travel around Cervinia, Aosta (Gran Paradiso), and Courmayeur (Mont Blanc) and have enough nights to explore those places
• About 4 nights in Piedmont (Turin, Alba, Barolo)
• 1 last night near MXP airport — we thought about Lake Orta and Lake Maggiore

We also have a few extra nights and thought about maybe going to Switzerland or to Cinque Terre. Do you think we should add them to our trip?

What do you think of the days division? Should we add something to the trip? Change the order of the nights? We're open to suggestions.

And if you have any suggestions for specific spots in the areas where we're already staying, I'd love to hear them.