I do suspect that the risk here might be too high as well, but I wouldn't rule this out entirely given where we're at now. Putin was very explicit in his statement that at this point Russia sees US and UK as being direct participants, that Russian citizens died on Russian territory as a result of a NATO strike, and Russia sees direct retaliation on NATO territory as perfectly justified. While there is a danger in Russia actually following through, there is also danger for Russia in NATO treating their red lines as a bluff, as that invites further escalation. Russia has been extremely restrained for the past three years, but that won't last forever.

There is pretty much zero chance that the US would start a nuclear war over Europe. Doing so would go directly against the US interests, and that would be the end of America. I'm quite certain that the oligarchs running the place would prefer not to spend the rest of their lives in a bunker. Europe would be left to hang if it came to that.

All that said, I agree that the most likely scenario is that Russia doesn't take the bait, and finds a way to respond asymmetrically in a way that would be unpleasant enough for US to drop the idea of striking within Russia. Ultimately, the best move is to respond in a way that will force the west to back off without inviting further escalation.