Florence: stay or daytrip ?

I think as long as the AirBnB is air-conditioned, is centrally located and is not up too many flights of stairs, you'll be OK. Florence is kind of in a bowl geographically and it has potential to be very hot, but maybe you'll get lucky.

Explore the best of Florence early in the morning or late at night, do your daytrip to Siena maybe on a non-scorching day, and take frequent breaks back at the apartment or at a cafe with A/C.

You should stick to your plan. I’m not sure I would define Florence as a zoo on a July weekend. Most Florentines will head out to their beach or mountain homes on the weekend, Italians also rarely visit art cities in summer, because they are too hot (they’d rather go to the seaside), therefore the zoo will have mostly only exotic animals from foreign lands. The extent of crowds is heavily depended on where you are in Florence. Major sights and piazzas may be crowded, but there will be areas where there won’t be, anybody, so where is your B&B? 4 nights in Florence (=3 full days) is ideal because it will give you two days for the city and one day for a day trip somewhere. Heading to Padova from Florence will be simpler too. It will be hot, so make sure they have a/c and avoid the top floors, which get hotter.

Thanks for those answers !

Having AC was a top priority when we wre looking for accomodations !

Our Airbnb is at 5 minutes walk from train station.

https://fr.airbnb.ca/rooms/7070194

I would keep with your stay in Florence.
As soon as you get out of the Duomo/Uffizi area, Florence is less crowded.
Cross the river, and wander the back streets; also beyond Santa Croce is fairly quiet in comparison.
Your apartment looks really lovely! good choice; but are you aware that the bathroom looks as if it is only accessed through the bedroom, meaning whomever is on the sofa bed has to walk through your bedroom to get to the loo?
That's what the photo shows.
At least it has air conditioning.

I cant remember if we have noted this when we made the Reservation but since we only be 2 ( my wife and me) its not a problem at all.

Can someone tell me if location its good...any good restaurant in that area?

Thanks !

I am not sure where your rental is located, but Florence (in my opinion) is easy to navigate. Here are a few I have enjoyed:

1. osteria del cinghiale bianco (www.cinghialebianco.com)
2. restaurant Il Latini (www.illatini.com) - I am sure you need to make a reservation
3. perseus (no website) -- I thought the food was better than Il Latini

All are rated on trip advisor. All were good. Il Latini is probably in all the guide books. It is "fun" -- lively crowd and staff.