I have 3 EVs: S, X, and a Volt. I'm on a TOU plan with a separate meter for the cars that provides ~$.05/kWh between 1a-5a.
Both the S and the X have high amperage charging enabled (dual on S, 72A on the X). I have two "old" HPWCs on 100A breakers, and the S and the X are plugged in whenever they are in the garage. We use scheduled charging at 1am.
The Volt uses a clipper creek CS-25 plugged into a 14-50 that is wired to our house meter. The Volt is our kid commute car, which drives ~32 miles round trip, twice a day. Because it has a small battery, we have to charge it mid-day and overnight, making the TOU option more expensive. Yes, I could wire a transfer switch, but I would never recoup the investment. Besides, the Volt will be replaced with an M3, at which point I will move the 14-50 to the TOU meter, or install a third HPWC. I will need to dial down the amperage to fit all three within 200A, or use a load-shed/balance mechanism. The UMCs stay in the car for the occasional on the road outlet charging.
To make this all work I had to upgrade our service to 600A, and install a 200A panel in the garage for the EVs. I have a second panel in the garage which is on a 135A breaker as a sub to one of my house panels where our solar system is fed, the Volt, and a few other misc circuits.
Supporting multiple EVs with a small TOU window (4 hours) is a PITA. The graphs showing the house using >45kW overnight is amusing, though.