i decided not to go with 100A service after realizing what a strain on my local power grid that would be. On super hot days everyone in the neighborhood runs their AC and the voltage in my car drops from 243V to like 228V.
I just set my car to not start charging until 3am when the strain on the grid is low. That also gives me the benefit of a freshly charged car in the morning that hasn't been sitting all night slowly losing range due to vampire drain.