EVs charge mostly at night. In fact they can be set on a timer to charge after midnight when rates are cheaper. In many areas this provides an excellent match to wind power. During the high demand summer months, California offers a great example of this with wind picking up as the sun goes down.
Consider Texas, the most wind rich state in the country. They are building out wind rapidly. However perhaps not as much as they would like. The problem is that wind in Texas is night peaking but the load from air conditioning peaks in the daytime. Wind is not a good match to the Texas load as it stands. But if EVs were ubiquitous they could charge at night enabling Texas to better take advantage of their wind resource while reducing carbon emissions from autos and from the coal and natural gas power plants that would otherwise be required to charge them.
The graphs below are typical of summer load and generation profiles in Texas and illustrates the point well.
Similar profiles are observed in California. While it is true that the wind resource in late fall and winter is low in California, so to is their load. In the summer when there is the highest demand on the grid, wind power is very reliable and available through the night. In fact, if you look at the data, it turns out that wind power is very predictable in California.
The term intermittent can mean many things. The general understanding is that intermittent means unpredictable or random. However, the term is often applied even in the case of predictable renewable resources such as wind in TX or solar in the Southwest. In each case, suggesting that the resource is random is naive at best. See graph below of solar production from a CA based solar array. Even on the rainy day the array produces considerable energy. Of course on a rainy day, temps and therefore AC demand would be lower. Generally , clouds and rain are predictable in CA. The combination of advanced notice and load reduction minimize and possibly eliminate the grid stability ramifications that may be existent for high penetration of solar in other areas.