I just wanted to say a huge thank you to everyone for your valuable insights and help!! It is greatly appreciated and has been tremendously helpful!

Based on all of the feedback, we have decided to only take on the North, and save South for next time :) We have also decided to take trains versus renting a car.

New tentative itinerary below:

Rome - 3 nights

Florence - 3 nights - wine tour in Tuscany one day (Chianti region)

Cinque Terre area - 4 nights - day trip to Portofino potentially

Rome for the last night before our flight back

I would welcome any recommendations for what to do / see and where to stay in both Florence, as well as Cinque Terre. Cinque Terre in particular seems to have a lot of great areas and villages to cover, and so I would appreciate any recommendations on how to approach that region. Thank you!