Buongiorno,
I suggest that between the third and fourth day you look at adding either
Volterra:
https://www.discovertuscany.com/volterra/
or one of the day trips in this article:
https://www.discovertuscany.com/san-...gimignano.html
I mean there are lots of things and places to go - but if you are looking for new destinations then either one of these articles will fill your day.
Another suggestion would be to split
Cortona and Arezzo in two seperate days....slowing down you pace and giving you just a bit more time to enjoy everything.
Buon Viaggio,
Donna Denise
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