My wife and I will be staying Florence and want to go to the opera at Torre del Lago. I'm considering a train to Pisa or Viareggio or possibly renting a car. I'm thinking we'll need to stay overnight, since I don't think we'd be able to get a train late enough to return to Florence and if we go by car, I doubt I'd be able to return it after midnight.
Does anyone have a recommendation for how to do this without too much hassle?
You probably want to stay overnight as traveling any distance late won't make for a special evening. The Puccini theater website gives numerous hotel ideas: http://www.puccinifestival.it/en/tourist-information/ And a blogger friend had a good stay at this B&B: http://ciaolunigiana.com/la-viareggina-viareggio-versillia/ Torre del Lago is not all that far from Viareggio train station, so a taxi would be affordable, but I didn't see a reference for transport after the show.
My inclination would be to rent a car and make a Puccini tour. The Puccini museum in his former home is also at Torre del Lago and it's really interesting to see the furnishings and the many mementos. In Viareggio you can see the outside of the home he had built there in 1921. In addition to touring nearby Lucca, you can visit Puccini's birth house there, and Lucca offers Puccini oriented musical events from time to time. Some other locations are mentioned here: http://www.puccinifestival.it/en/luoghi-pucciniani/