I don’t know why they are talking about the east coast. The Russians have have well over 1800 nukes ready at a moment’s notice, and the entire nation would be destroyed in minutes (as would theirs).
The whole point of huge nuclear arsenals is to achieve mutually-assured destruction (MAD).
Here’s a list of US Metropolitan Statistical areas, there are only 300-some odd places, and hitting them all wouldn’t be difficult. We can also assume that every power plant, dam, military base, etc would be targets.
A full-scale thermonuclear war is inconceivable and unwinnable. We don’t want it, and the Russians don’t want it. It would obliterate civilization.