Train or car or both needed in Northern Italy ?

We all like a different pace--have you done a trip this long/with this much moving before? It would be completely doable by train/bus, no benefit from a car (you'd spend more time looking for parking than seeing countryside).
Now should you consolidate a bit? I would! I look at the overall balance of a trip versus feeling like you need a certain number of days for a specific place, etc. I just don't like moving on after two nights, but you have to consider your own personality.
Will doing laundry in Florence get you though the rest of the trip?

None of those locations in your plan as you currently have would need to have a car. Everything can be accomplished by train (or bus for Siena). Obviously when traveling by train you must be judicious about your packing, because traveling by trains and buses is cumbersome with heavy luggage.

My preference is usually to minimize hotel changes, since the process of checking in and out is time consuming. Some of those locations can be visited as a day trip, if you want. Orvieto is less than 1.5 hours from Rome by train. Siena is only 75 min from Florence by bus. Lucca is 1.5 hours by train from Florence. I understand that Siena and Lucca are smaller cities compared to Florence, but there are neighborhoods in Florence that make you feel like you are in a smaller town rather than a big bustling city.

Thank you for your very thoughtful feedback, I greatly appreciate it.

Suggest you cut down the number of stops, because with what you are planning, relocating from one hotel to another will overwhelm the time left for enjoyment.

“Travel less, see more”

We felt staying a night in some of the towns would be better than just
a day trip but is staying in 8 different hotels just too chaotic ?
Would some day trips be a better idea ?

You actually have 9 hotel stays on a 16 night trip…so I’d have to say not only chaotic but also exhausting and very unproductive.
Each time you change locations you lose a half a day- check out, get to train, ride train, get to new lodgings, check in, get oriented.
If it’s just a 1 night stay you have some of the afternoon and 1 evening to enjoy that town. Get up in the morning and do it all again.
A 2 night stay isn’t much better but at least gives you a full day and a half day.

Is this your first trip to Italy? Are you used to traveling at this pace?

You are shortchanging Rome (unless you’ve been there before). Your first day there is jet lag so doesn’t really count for much.

We have found we don’t even like day trips much anymore. Hate 1 night stays (only if really necessary like a 1 night on arrival or before departure- sometimes just can’t be helped).
Some places really only need 2 nights.
If there is a town we are interested in we go ahead and give it 2 nights- plenty of time to wander, enjoy, visit a few sights, go to the am market, etc.

I’d try to consolidate and cut out a few stops. 5 locations on a 16 night trip is still a bit fast paced but better.

Lucca- We spent 2 nights last spring- it was just OK didn’t find the “charm” there that is often mentioned in guide books. With just one night you wouldn’t have time to bike or walk the amazing wall or visit a morning market.

Siena- loved this town and an overnight is delightful but can also easily be done as a day trip from Florence.

Orvieto-loved. I’d give it 2 nights- easy to get to from Rome and a nice break after the busy-ness of Rome.

Florence- 4 nights with a day trip to Siena is perfect. (We've been to Florence multiple times- spent 4 nights there May 1- it was unbelievably crowded! We couldn't wait to leave, wished we had only allotted 3 nights- so getting away for a day will help even though Siena will be quite busy as well)
Another option is to take a guided group bus tour that gets you to several Tuscany hill towns- there are several.
ToursbyRoberto is one, Walks of Italy is another)

CT- it takes some effort to get there so I’d give it 3 nights. Expect crowds. (A 2night stay is only 1.5 days there).

Parma- have not been but seems to be the outlier here. You’ll be traveling 2.5 hours NE for a 1 night stay then have a long approx 3 hour trek to Lake Como (must transfer in Milan).

A fun tool to help you determine travel times/transit options is
www.rome2rio.com. They also have an app
Just use it as a staring point.
(Orvieto to Siena you will need to train to Florence then transfer to bus or train to Siena or train to Chiusi then change to train to Siena- both take at least 3 hours.)

Be brutally honest when you plan your days- write down all the steps it takes to get from one place to another and allow plenty of time. (A transfer is not just the time it takes for the train station to station)

Suggestion:
Rome 4
Orvieto 2
Florence 4-with day trip to Siena
CT 2 or 3
Como 2 or 3
Milan 1

All easily done by train.

Can you reverse the trip and fly IN to Milan OUT of Rome?
Rome is a bit hectic for a first entry to Italy- my favorite city but doesn’t feel like a big city-
Como would be an easier entry and a nice place to get over jet lag and you can go there on arrival skipping a 1 night stay in MIlan.

We spent time in Stresa (Lake Maggiore) this past Sept. Flew in to Milan and went right to Stresa- it’s actually closer to MPX than MIlan is. From there we continued easily on to Bergamo- Bologna- etc.
We had to fly home from Milan as well and we gave it 2 nights rather than 1. Weren’t really crazy about the city itself but it was absolutely worth it for The Last Supper and Duomo.

Slow down, you will be back.

Train companies are:

Trenitalia- fast trains and regional
https://www.trenitalia.com/content/tcom/en.html

Italotreno- fast trains
https://www.italotreno.it/en

Both have easy to use apps. I think May schedules should be up by now but if not just use a same day of week to see what May should have-schedules don't change much.

Info on trains in Italy:
https://www.seat61.com/train-travel-in-italy.htm

Hello rpreefer,

I'll reiterate everyone who says all of this is easily can - and should - be done by train and maybe the occasional bus.

I do think you're trying to make too many hotel changes - I would advocate for longer stays in base places and use day trips to see the surrounding area. A day trip is a good way of getting the feel for a place and then you can decide it goes on the list for more exploration next time. It's really a trade-off because day trips always have a clock on them when you need to get headed back but changing hotels costs you half a day involve much more hassle - packing, checking out, bags on the train, checking into new hotel etc.

The travel day from CT to Varenna in Lake Como is going to be a longish day - probably 4-5 hours on the train and changing trains in Milan. Be sure to factor in travel time when planning on how many nights you're going to be staying in a place because coming in the afternoon and staying two nights is 1 day and 2 part days rather than a 2 whole days. Consider 2 days to be a brief stop someplace and I would only ever suggest staying one night somewhere if required by transportation - eg the night before you fly out the next day. If you're only giving it one night and can't give it two then do it as a day trip or save it for another trip.

Lucca and Siena are easily done as day trips from Florence so I would extend your time there rather than move everytime.
Lucca is light on "sights" so it is mostly old town ambience (I really like it) and everyone loves Siena.
Parma is kind of the off city out for one night there but only you can decide what's really interesting to you and worth spending time on.

Have a great trip, solid planning is a great start,
=Tod

We visited many of those towns in Sept-Oct. We used trains save for the Siena-Florence leg, which is best done by bus.

Trains were prompt with minor exceptions. Thus, I would plan on arriving at the station with 30-45 min time to train. We also found the platform changing in a case or 2, so be alert.

I would pretty much go in the order that you listed in the OP.

I agree with some of the comments about the rushed nature of this itinerary. I would choose either Orvieto or Siena, skip Lucca, and do 2 nights in Parma. Acknowledge FOMO (fear of missing out), and recognize that each choice to do something means that you will not do something else.