While browsing other parts of the web about Cold War Europe and also reading this thread, I found the following page that has some interesting claims about the situation in the two Germanys: -
https://www.slate.com/articles/news_..._mattered.html
Specifically this section, although it should probably be noted that some of this appears to be the author's opinion: -
"By October, the Soviets had closed off all but one border crossing. On Oct. 27, in a now-forgotten confrontation (one year before the Cuban missile crisis), Soviet and American tanks faced each other along that checkpoint, at short range, for 16 hours until negotiations were held and the Soviet tanks backed off. The crisis faded.
There would never be another crisis over Berlin (which may be why all the previous ones have largely been forgotten). The Soviet rulers had no need to threaten West Berlin as long as the wall kept their own people locked in.
The wall was built to bottle up an incipient revolt—a mass emigration that threatened to expose the Soviet system as inferior to the West, as an oppressive dungeon that its most educated young people yearned to escape. The wall not only blocked those yearnings; it also made clear to the brighter young Soviet and Eastern European leaders that the system itself—the ideological basis of their rule—was suspect, that it could not be sustained, much less compete with the West, without the internal imposition of force.
Khrushchev was ousted by hardliners in 1964. For the next quarter-century, the Kremlin's leaders devolved into increasingly sluggish bureaucrats; the system itself bogged down more and more obviously. In 1988, when Mikhail Gorbachev set a course of serious reform and reopened the Soviet Union to the world, the possibilities that had been unleashed in the late 1950s, but suppressed ever since, once more bubbled up in the popular imagination. And when the wall came down, it was like a cork exploding."
This other site mentions some of the supplies stockpiled in West Berlin in the 1980s, including one year's worth of natural gas!
https://www.the-berlin-wall.com/vide...tockpiles-698/
That site has a number of interesting video presentations arranged by timeline. Some of them discuss the political opposition in East Berlin
And while I was caught up in finding more about possible stockpiles in West Berlin I also found this page from the New York Times in 1990: -
http://articles.latimes.com/1990-11-..._1_west-berlin
It specifically mentions
300,000 metric tons of food & other supplies and
280 warehouses around the city and mentions that the stockpile was
large enough to supply West Berlin for up to a year in the article about sending the food stored in West Berlin to the Soviet Union as emergency relief in November 1990.