It makes no sense to drive Florence to Pisa or Bologna. Those are easy,fast and cheap train rides.

If you want a car for Como rent it in Como or nearer to Como.

Yes, you absolutely don’t want a car. Because of ZTL issues you can’t drive into Bologna or Pisa. Train from Florence to Bologna 38 minutes and Pisa 60. Also driving in the Lake Como area is not recommended,

Car not needed nor desirable.

There are challenges with driving abroad, but in the main they are enjoyable ones to overcome. A road trip in Italy can be very rewarding - the issue is the places you’ve chosen to visit, which don’t lend themselves well to being visited by car, because you are focusing on large cities, where traffic is bad, and finding somewhere to park it will be expensive and a hassle (and although not a city, the same goes for a crowded tourist hotspot like Lake Como, where you will use the boats to get about when there, anyway). Whereas your itinerary, including the possible side trips to Bologna and Pisa, can easily be done by train, most of it comfortable and high-speed, which will drop you close to the centre where you want to be, in most places, or if not (Milan and Bologna, the stations are a little off) at a transport hub so you can easily travel on by bus, taxi or (in Milan) metro.

#3 actually Bologna isn’t so bad to visit by car, because you can park easily by the station (in the pay car park). Of course, you’re then no nearer than you would have been coming by train, but it isn’t fair to say that you can’t drive there.

You don't need a car. But if you really rent one, then don't give it back in Como City, but in Lecco. Becouse from there it is an easy and short train-ride to Varenna. If you don't get a room there, you can go a bit further on north to Bellano.

When talking about Lake Como we must not forget the particular shape of the lake and the fact that the city of Como is rather decentralized compared to the most scenic area of the lake, the central one, where the lake divides into two branches.

Furthermore, the railway runs along the entire eastern shore of the lake, from Lecco to Colico, but not the western one.

https://www.ideeviaggio.it/wp-content/uploads/2019/10/lago-di-como-mappa.jpg

Thank you all for all great advice. It looks like train everywhere and make it easier for us anyways.

We have had numerous driving holidays in Tuscany, Umbria and the Veneto but not visiting large cities for which the train will be best. A car is invaluable to reach smaller out of the way places, driving problems can be exaggerated.