I don’t know where you live, but the Californian power grid is part of the Western Interconnection that goes from the Mexican-American border to half way through Canada[0]. Are blizzards in the USA ever that big?
As for “at night”, it is possible to get batteries of household scale. Plus insulation is getting better and cheaper, so the power required to maintain any given temperature isn’t as high as it used to be.
At times of the year when there are blizzards, I seriously doubt the rest of solar installations in the US are going to be running anywhere near capacity.
First: So? PV is so cheap overcapacity isn’t unreasonable.
Second: My first visit to the USA, I saw people surfing in Asilomar on Christmas Day/Boxing Day and it remained warm and sunny throughout my stay in California, yet a few days into that trip New York was suffering a blizzard that Trump was trying to argue disproved global warming: https://en.wikipedia.org/wiki/Early_2014_North_American_cold...
