That's an optimistic assessment. The problem with nuclear war is that it's fairly hard to work out how one could have a "limited" one. There's far too much room for miscalculation and overreaction leading to the end of civilisation. Just like World War One was ignited by the assassination of one person, sometimes all you need is a spark to light the massive bonfire we're standing on.
For example, the majority of the submarine missile forces in the world would not actually be used in the first few days of the war.
Whilst a small number would be expended in an attempt to suppress air defences, the majority would be hidden in whatever bodies of water are available and convenient as a last ditch retaliatory weapon - or to maintain detterance after the war.
Whilst the enemy submarine force survives you are not going to go full-blown countervalue (attacking cities that do not contain major military infrastructure) because you know to an absolute certainty that they will respond in kind.
The majority of nuclear defence installations are actually in the middle of nowhere - and the vast majority of warheads that are actually detonated (excluding fuse failures, fizzles, weapons being caught on the ground, launcher failures and such) would be detonated in what is best described as the middle of nowhere.
Indeed political infrastructure is often projected to be ignored during the early stages of an exchange, because you need someone alive to negotiate with if you want to avoid the surviving command infrastructure assuming all is lost and thus attempting to get every missile out of the ground
right now.
Meanwhile bomber and missile forces, especially those attacking Russia, would suffer heavily from the logic of air defence - sacrifice the few to save the many.
Even the vaunted Stealth Bomber can be eliminated by detection by HF radars, followed by a pattern attack with nuclear tipped surface to air missiles - overpressure will kill the bomber even though the fix is only accurate to a couple of miles.
So whilst there would be a large number of bursts, many would be of surprisingly low yield and in places which are not particularily heavily populated.
Montana would get hit hard, but there are not many people around to notice.