Stay in Treviso or Vicenza (2 nights). Recommendation for place.

My husband and I loved our 6 nights in Treviso, staying in this great apartment which may work for you if your sister is OK with sleeping on a comfortable sofa bed: https://www.airbnb.com/rooms/23622993?guests=3&adults=3&s=67&unique_share_id=88cb4a5d-cdfd-4a03-9905-0e2803d5db07 You can read my long review from September 2019.

Treviso itself is lovely and interesting, with canals and bridges, plenty of great places to eat, frescoed Venetian-style buildings, old city walls, interesting small churches and museums, a fish market on an island, some cool wire mesh art installations on some of the walls of the buildings, and many pedestrian-only streets and porticoed sidewalks. If there were tourists there, they were Italian.

Here's some of the wire mesh art of Mario Martinelli in Treviso: https://www.mariomartinelli.it/en/ombre-rete/

Our apartment was about 500 feet from the island fish market and 100 feet from the very interesting civic museum. Loved that neighborhood, but there are lots of nice areas in the old part of town. You could easily spend your whole time in Treviso.

Never been to Vicenza, so can't compare, but I'm really happy that you will also stay in Padua and Verona!

Thank you so much. Apartment is available. Are beds same size? Bedroom one bigger? I am gonna try to book it right now. Thank you so much. So we can do day trips from there for four days? Sounds good!! I like staying in one lace longer. Are wee fine on bus and train??

Only one bedroom --- the sofa bed is the living room couch. I think, but do not remember, that the sofa bed is a double and the real bed is two twins stuck together (a very common practice). You could ask the host. Look at all the photos very carefully --- the living room, dining room and kitchen is all the same room.

We had a car, but there is a train station, and I'm guessing a bus to other towns.

hey hey LetiCalifornia (hi neighbor)
my opinion is go to treviso. you can always take a day trip from padua or verona to vicenza.
rossiwrites.com/treviso italy
wanderlustduo.com/visiting treviso italy travel guide
home to tiramisu, crowd free and a hidden gem, historic center, cobblestones and canals, near the prosecco hills.
visitproseccoitaly.com
click travel guides and scroll down, read about day trips to different towns in area or things to do in the town. few years back 4 of us bay area friends took the tour with oriana (fabulous & funny guide/driver). she was born and raised in this gorgeous lush green area. enjoying lots of prosecco tasting at 3 local wineries, lumch at a small family restaurant, couple friends walked up to outside vending machine, it was wet & muddy but lotsa fun. took train from venice to susegan, met here the tour was longer back then then back to susegana station and our ride back to venice with few bottles of the local prosecco and "happy hour" at our apartment in canareggio
with your airbnb, top of page has "stays experiences" fill in sitting and dates and see what they offer with tours/things to do.
how many days/nights will you be in venice, exact dates, budget in euros, look at transportation if flying into venice and where will you depart from (you can do multi-city "into one city depart from another"
europeforvisitors.com
lots of info here, keep asking questions here on the forum and posters/regulars/old time travelers will give you the good bad and ugly. it's you decision to choose. you will have a great time and so much fun with research of what's a must on your list, okay if we miss, and no can do. your list will get long but don't overdo, give time to soak in the culture and beauty, sit outside cafe and watch the world pass by. "bang bang niner gang GO NINERS!!"
aloha

We loved our stay in Vicenza in a country inn, Le Vescovane , a few miles outside of town. Beautiful place.
www.levescovane.com

I've stayed several nights in both but prefer Vicenza although both are very nice towns.

My suggestion is to sleep in the cozy beautiful Vicenza. Absolutely stunning piazza dei Signori and the little hidden corners with market and Palladian architecture!
I stayed at airbnb B Suite @ Olympic Theatre right 3 min walk from teatro olimpico
https://abnb.me/5wtNje0ErIb

Enjoy your visit :-)

Thank you for the 2 Vicenza lodging recommendations Suki and mgiometz. Both towns are charming, but I prefer Vicenza. The Palladio buildings in and around town are so very unique. Vicenza has a nice 'square' and main street. Get a walking tour map to learn more about the great architect, Andrea Palladio.

Treviso has an excellent restaurant, https://www.lebeccherie.it/en. We had a great lunch there with their signature dessert, Tiramisù.