Extra Luggage storage options in Rome

You should be able to store your extra luggage in the "deep storage" section of the tour bus. Be mindful that you may have to store your extra luggage in your (probably small) first tour hotel room until it's time to move to the next location and the bus driver arrives. Once you get to the last destination, the bus driver leaves and you will have to retrieve your extra luggage and store it in the last tour hotel room.

storage options in Rome, where we start and end the Rick Steves for the whole week of the tour,

Which RS tour are you on?

We are taking the 9 day Heart of Italy tour starting in Rome and ending in Florence. Then taking the train back to Rome and flying out of Rome. So I’d like to store a larger bag in Rome from the previous cruise. Maybe write the final hotel and see if they’d keep it a week. Or are there storage lockers around the city?

Please see this previous discussion that mentions baggage storage at Rome Termini stations.

https://community.ricksteves.com/travel-forum/italy/luggage-storage-in-near-termini-rome

Couple of years ago we passed through Rome on our way to second tour in Spain. The Rome Hotel stored some of our bags that we picked up when we spent a night there on our way back to US. The convenience is worth the extra night if required. You will love Italy.
Safe travels.

You can look at stasher.com - they have multiple locations in Rome. There are other similar left luggage services as well.

This is all very helpful. Thank you so much!