Rome and Florence centrally located places to stay

Florence is very compact and walkable
Any place in the historic center between Duomo, Ponte Vecchio and train station works

Rome-in the historic center near Pantheon/P Navonna/Campo de’Fiori is good
Can walk most everywhere from there

He might get a kick out of a monastery stay. We stayed here - Casa per Ferie Suore Oblate …Borgo Pinti. Cab driver said it was the best location in Florence. Check it out on monasterystays.com

Florence should be easy, very small area but I think Rome needs some planning to only walk a few miles each day. Yes, a centrally located hotel helps & agreed with poster above about best areas. Then you have to get to wherever you're going and WALK through the museums & find somewhere to eat & then get back to your hotel. And museum walking just isn't the same, it's slow and harder on the feet, as are cobblestones!

Our preference is to get out as early as possible to roam around, visit one museum and have lunch (always planned before leaving hotel) before returning to hotel to put our feet up and rest before venturing out later in the afternoon. We tend to take taxis one way & walk back if it’s more than a 30-min walk to destination, and even with that, we walked 12,000-15,000 steps, (up to 9 miles) every day. If you'd like to read the longer version, it's here. https://community.ricksteves.com/travel-forum/trip-reports/rome-was-jammed-over-ny-but-still-fun

We loved the Hotel Balusteri near the center of Florence, on the Arno.

In Rome, consider a hotel near the Pantheon.

The Colonna Palace Hotel is very centrally located and most important sites are within walking distance. There's also a very busy bus stop 2 or 3 blocks away which is great in case you need to take the bus someplace.

In Florence, check out the Hotel California. Yes, that really is the name, and you can walk almost every where from there. It's really a beautiful place to stay.

I should have added we really liked Hotel Smeraldo, wonderful staff, close to the Jewish Ghetto & about a 15 minute walk from Piazza Navona. Book a 'quiet comfort' room facing an inner courtyard, the outward facing rooms are NOISY.