FQ, You are overlooking some things, first off, Nuking the Northern invasion fleet is a non starter, by the time the politicians in Washington realized what was going on, built up enough courage and then talked to Canada about it, things would be all over. Even if politicians did get off the mark and decide to nuke friendly territory in a timely manner none of our weapons where aimed at the middle of nowhere. The whole premise of MAD was the targeting of each other's cities, you don't re target an ICBM by just cranking in a few clicks on the scope, also this was prior to GPS which means that it would have been all manual map table calculations.
On top of that, the effects of nuclear torpedoes would have been hampered by the ice itself, limiting the effectiveness of the few that could be brought to bear in time to have any effect.
As far as the logistic tail of the Southern operations, it was irrelevant. Their job was not to win any kind of decisive victory, simply to sow confusion and draw off troops from the primary AO, foraging would have supply enough resources for them to accomplish their primary mission, any actual gains they made would simply be icing on the cake. You have to remember, The Soviet leadership of that time were WWII veterans where they issued one guy a rifle and 5 rounds, the 4 guys after him just got 5 rounds and orders to pick up his rifle when he was killed. casualties did not have the same impact on their society that they do on Western societies. Another thing to bear in mind was that Soviet stratagy fucused on reinforcing success, advancing units got resupplied and reinforced at the expense of stalled units, and all units were simply pushed to advance as long as they survived then new divisions were thrown in behind them.
Also, at that time, according to the declassified portions of the Mitrokhin Archive, (The Sword and the Shield Pgs 392-393 ) Breznev's successor, Former KGB director Yuri Andropov, and the leaders of the Politburo were so convinced that Reagan intended to launch a nuclear first strike that much of the KGB's First Chief Directorate was tasked with searching for information on US intentions under the auspices of "Operation Ryan".
And then there was Spetznaz. Remember our "ReForGer" exercises ? Return Forces to Germany , we practiced defending the Fulda Gap, and reinforcing our troops in Germany on a regular basis. Spetznaz practiced screwing up those types of operations just as carefully. The primary mission of many of the Soviet "illegal" networks ( operatives inserted under false identities and non diplomatic covers, such as the 11 arrested and exchanged a year or so ago ) was establishing equipment dumps for exactly that sort of operation.
The work of the US military in responding to invasion on multiple fronts would have been severely hampered by wide spread attacks on transportation and communication hubs. Among the items standard to Soviet Operational planning was chemical weapon attacks on nerve centers such as command posts and air fields. even with warning, and limited casualties efficiency at such points would have been greatly hampered by the need to work in protective equipment. To get an idea of what I mean, try disassembling your Sportical wearing winter gloves, a snowsuit and SCUBA mask, then consider how that would be trying to maintain jet aircraft.
Warhawke presents a frighteningly simple and effective plan.