Hi, I'm just starting to plan a trip next Sep-Oct to Northern Italy then Croatia. My husband and I are in our 60s and in decent shape--love outdoors, moderate hiking and sightseeing; we're not big into history/museums but strive to see the major sites. We've been to other parts of Europe a handful of times and about 10 years ago, we visited Rome, Florence, Sienna, Venice, and Sorrento so we are interested in the areas we haven't been. My husband enjoys driving so we plan to get a car, specifically to drive through the Dolomites. So far, I'm considering flying into Milan, driving to Lake Como region for 2 nights, then Cinque Terre for 2-3 nights then Dolomites for 3-4 nights. I assume we'd pick up the car in Milan and return it in/near Venice with possibly taking a ferry from there to Pula, Croatia. Other than the Dolomites, I'm not firm on the other locations. We generally appreciate smaller villages and try to avoid larger cities other than to see major sites. I understand that both Cinque Terre and Lake Como are very touristy so if you have other suggestions, I'm open to them. I admit I haven't spent much time in the forum to review similar posts so feel free to send me links instead of responding. I appreciate your suggestions!
On your way across northern Italy here are a few suggestions for your consideration: Bergamo, Brescia, and Verona ( the historic city center is compact and relatively flat). Since you will have a car explore the northernmost small towns of Lake Garda like Riva del Garda or Limone sul Garda. On your way to the Dolomites stop at Trento. The historic city center is compact and easily walkable. lLike much of that area, you get quite the combination of Austrian/Italian foods, architecture, languages, etc. Lots of people visit Bolzano. Merano is a pretty mountain town north of Trento. I have not been to Bassano del Grappa but it is pretty and is often recommended here on the forum. I did like Vittorio Veneto which is totally off the international tourist radar.
You said you may take a ferry from Venice to Pula but should you decide to skip Venice you may enjoy Trieste and there may be a water route from there to Croatia. If you do go to Venice -Vicenza, famous for its architecture, is on your route and Padova is a popular stop not far from Venice, or even consider a visit to Ravenna to see the spectaucular mosaics if you are into religious art. Another alternative to Venice that may also offer water transport to Croatia ( I have no idea, you would have to research that) is Chioggia. I have not been there but it has been on my radar for a while since it is a city with canals.
Lots of possibilities. Good luck with your research.
If your plan is Milan > Como > CT this section really doesn't need a car. Access to a car will open up some towns that are not accessible by train but driving around the lake can be a slow and frustrating experience depending on traffic since there is one road. A car in CT will be an expensive burden and is completely unnecessary.
If you are set on CT then you could go Milan > CT > Bergamo > Brescia > Verona by train and then rent a car and do Lake Garda on the way to Trento and the Dolomites and then drop off the car and see Venice. Or add Lake Maggiore which is closer to Milan MXP anyway and then move on to CT. The train does serve anything except the lowest end of Lake Garda so your options are bus or car so this is a good place to have the option of the car.
Brescia has amazing Roman ruins, adjacent museum and castle on top of the hill as well as a series of great piazzas.
Verona is great, pedestrian town with an upscale cafe culture feel to it.
Additional small town suggestions Mantua/ova is a day trip from Verona.
Bologna is also in the mix with good fast train service but is south away from the Dolomites.
You have the problem of too many options, hope that helps,
=Tod