driver from Florence to Menaggio on Lake Como

The site Rome2Rio is great for seeing your transportation options. A private driver for that trip (almost 5 hours) would most likely be VERY expensive.

If you consider that a private driver from the Rome airport to Sorrento (over 3 hours driving time) on average costs €550 for a party of 4 (minivan), imagine what it would cost a trip that is 5 hours long.
The best option, in my opinion, is the high speed train from Florence to Milan Centrale. Then at Milan Centrale you take a regional train to Varenna. Once in Varenna it’s a short walk from the station to the ferry dock. There you take a ferry across the lake to Menaggio (10-15 minute crossing).
There are several trains a day (at least one an hour) and you can be in Varenna in less than 3 and 1/2 hours from Florence (an impossible feat by car, even if you drive a Ferrari with no traffic and make no bathroom pit stops).
Train info below:
https://www.trenitalia.com/en.html
Enter:
From FIRENZE SANTA MARIA NOVELLA
To: VARENNA-ESINO
Date; choose any date however the summer timetable eff. June 11 may not be available yet, but you can test a date sooner.
Time: choose a time of departure you like (use military time)
Check the solutions with only one change and are shortest.
You can buy in advance a discounted fare (Economy, Supereconomy, or other group offers) if your time of travel is firm (discounted fares are non refundable and non changeable once you book a specific train).
If you want more flexibility because you are not sure about the time of travel you can buy the tickets when you get to the station in Florence on the day of departure. In that case you will likely pay full price, called BASE price, since discounted fares are generally sold out if you wait till the day you travel. Unlike airplane tickets, the train fares don’t change as you get closer to the day of travel. The BASE price you can see today on line is the same you will pay even if you wait to buy it a few minutes before departure.
The full BASE price is €62.90 per person on the Standard class. If you are in the position of buying a non refundable non changeable Supereconomy ticket you can save as much as over €20 per person, bringing down the price to about €35 per person. So the 4 of you could get there at least one hour faster at a fraction of the price you’d pay for a driver. I didn’t check the ferry prices but I think it’s under €4 per person.

As a compromise, take Business class Florence to Milano Centrale, then change to EC 1st class to Como San Giovanni for 166 EUR total for 4 when you buy a Summer Promo Special now. Then a taxi to Menaggio for about 75 to 100 EUR.