We are staying outside Florence central in a town near San Casciano. Is there a testing site which would work for us without going into central Florence?
What airport are you leaving from? Fiumincino has a test site. Pisa Airport has them in the morning, and Firenza airport does them - both use this: https://aeroporti.misecup.com/
This thread has a search site listed: https://community.ricksteves.com/travel-forum/italy/for-u-s-a-citizens-needing-a-test-to-go-back-to-your-home