Driving from Geneva-Verbier- Florence?

You will pay a lot to pick up a car in Switzerland and drop it in Italy. The car will then have to be transported back to Switzerland and you will pay for that and more. I don't know if chains are required, but it may be wise. The road to Verbier from Le Chable has about a dozen or more severe switchbacks as it goes straight up the side of the mountain. Then getting from Verbier to Italy down those switchbacks and then to Brig, and either more switchbacks over the Simplon Pass, or use the Simplon car transporter through the Simplon Tunnel.

Going by train is pretty easy. Train directly from Geneva airport to Martigny, change to train to Le Chable, gondola to Verbier, You will be there in 2 1/2 hours. To get to Florence, leave early (6:56 am) gondola back to Le Chable, then train to Martigny, train to Brig, EC train to Milano Centrale, then Frecciarosso high speed train to Florence SMN. Just over 6 hours. There are many later departures, but take longer and have more train changes.

It would fully depend on how much time you have to make the journey. Can you do some fun stops along the way or would you have to do the whole 7 hours?
Driving to Verbier is about two hours (not one I'd do after flying), but the train is really not that much longer (Swiss trains are such a joy).
What was the drop off-fee you were quoted to take the car to Italy?
There are not direct flights unless you fly to Rome (but that's an easy hop to Florence).
Others can expand on the seasonal aspects, good luck!

Anecdote time. My first visit to Verbier was 30 years ago, and we LOFAO when it was snowing heavily and we watched a car spinning its wheels in the snow. They had chains and put them on, but on the rear tires of a car with front wheel drive!

Thank you for all your replies. Truly appreciate it.

Update. We decided against the rental car. It was costly as you all suggested it would be. Taking the train. Looking forward to relaxing and enjoying the scenery.

hey hey kristen
happy you decided not to rent car. curious like valadelphia about charge for drop-off fee from switzerland to italy. few years ago friends did southern france (st jean pied de port to barcelona spain) was $950!! ouch they didn't know about fee until it was too late.
plus would have needed an IDP (aaa.com/IDP) which is mandatory for italy, don't know about other countries. you'd need to look it up and have the permit before leaving states. something to think about next time if you travel to europe.
do you have transportation from geneva to verbier?
it's gorgeous country, we took train paris to geneva for two nights then taxi to annecy about 35 minutes. loved annecy and the small villages around all the beautiful view and mountains. enjoy and have a great time.
aloha

Transport schedules are at www.sbb.ch/en
Geneve Aeroport as the start. Verbier, Medran is the name of the lift terminal in Verbier. Firenze S.M.N. is the main station in Florence.