It's pretty simple, we will burn more fuel to charge the EV's.
FWIW, NG consumption in power production has doubled in just over 10 years, and shows no sign of slowing down.
Again, peaker plants make up for solar/wind intermittency, and result in even more NG consumption, than if a NG comb cyc plant was used without solar/wind. In other words, solar and wind ain't helpin'.
As expected, Hydro, Coal and Nuclear are being decommissioned. NG will make up the difference. Expect another doubling of NG consumption.