La Pasquetta travel from Florence to Siena? Good or bad idea?

It is tradition for Italian families to go out on a “Gita fuori porta” (lit. a tour outside the city walls) on that day. Usually it’s a day (or 2 day) trip somewhere near within a couple hour drive. Many Florentine families will take advantage of the holiday to travel to those places, like Siena, San Gimignano, etc. My memories of Pasquetta in Tuscany was a lot of bumper to bumper traffic driving back to Florence in the evening, especially on the freeway from Siena. If you go by bus, be aware that the buses will run on a holiday schedule (I.e. less frequently). Since the bus will equally be stuck from before Tavarnuzze all the way to Florence, you might consider taking the train back to Florence. Normally the bus is 15 min faster to Siena because the train has to take a longer route around the mountains through the Val d’Elsa and Empoli, but on the evening of Easter Monday I’m sure the bus will encounter traffic, so the train might be faster. On the way there, traffic will be ok. But on Monday evening you have day trippers and weekend travelers coming back to Florence from all over Tuscany, so traffic will likely be a zoo, especially if the weather is nice. Take the train back.

Thanks for the advice. So do you think it would be OK to go to Siena that day or should we just stay in Florence and go maybe on Thursday 5 April?

Actually maybe we'll just go to Siena on La Pasquetta and as you said take the bus there and train back. I feel like it will be hard to do many things in Florence due to museum closings and many tourists in Florence. I appreciate your advice!