The standard for Cold War planning was the Teledyne-Brown raid, modeling a Soviet attack on the U.S., involving about 6000 nuclear weapons, more or less all at once. IIRC, the Detroit area was one of the prime targets, receiving more attention than just about any place except Washington, DC. I seem to remember in excess of 100 rounds targeted against the Detroit area. 12 miles NE of Detroit would be indistinguishable from ground zero.
Thanks for the info.........at my age, I'll take my chances right where I am.