`i read there is a prediction of another unusually cold winter, like last year. The grid barely handled the higher output. True, there are modernizations that would help, but a large limitation is the method of generating electricity. To instantly provide electricity to the grid requires methods that have fuel readily available and, weeks, if not months of supply at hand. There are only two such sources -- coal and nuclear. Wind generation efficiency dips as the temperature drops -- many are taken off line. Solar, of course, is only available during sunny days. Dams,, especially up north, lose power as the rivers freeze. Natural gas can't be stored economically onsite in sufficient amounts (there are safety concerns, as well). If, the supply is interrupted, power generation drops immediately.
One good cold winter and interrupted natural gas supplies and no cola backup will be a disaster.