Northern Italy

Don't overlook the enjoyment of spending 2-3 nights in Milan! Perhaps there and one other place?

With just 6 nights I would just stay in Florence. You could do some day trips, for example to Lucca and Pisa, or even a Chianti tour, without spending any of your limited time on moving locations.

Advantage of CT in March, no cruise ships/tourists! Disadvantages: weather can be stormy, rain. Ferries not running. Many of the hotels and restaurants shuttered, especially in the smaller villages; hiking trails also closed.

Torino? Genoa? Limit travel time and be closer to Milan.

You’ll need to stay in Milan night before departure.

Go directly to Florence or consider Bologna 4 or 5 nights
Back to Milan for 1 or 2 -especially if you have any interest in the Last Supper

Sorry, I should have mentioned we have also been to Milan many times and I will be there for work for a week prior to these six days of vacation.

Understood weather can be iffy in March in Cinque Terre which is the main reason I am questioning it.

Was also considering Bologna or Genoa or Chianti region... thoughts on these?

Chianti region is wonderful. We have stayed there four times. Rent a car in Florence, drive to a Chianti town and stay there.

The C/T is more of a Summer place to visit. From Milan north to Lake Como area is hit or miss for March. Sometimes it's nice, and sometimes it's still winter. An alternative place to visit might be Lucca if you're want a quiet place.

We were in Florence (and Rome) in June for the umpteenth time, and I'm just tired of crowds--and labor strikes by train workers. We're more of the rent a car and see the countryside types.

Last year we visited the Cinque Terre from March 20-23. We also visited a couple of other riveria towns. The weather was sunny and it wasn't crowded. If the weather was rainy we would have been more limited (we did the hikes for each town referenced in the Rick Steves guidebook) but still would have had a great time.

If you enjoy good food, Bologna is a must. It's a 1 hour 14' train ride from Milan. It's also a beautiful city, but what city in Italy isn't?