Yes, a 4-6 hour "main report" of the party leader to the congress was the norm throughout the time when the [CPSU](https://en.wikipedia.org/wiki/Communist_Party_of_the_Soviet_Union) was in power.

I remember having to study the [Gorbachev](https://en.wikipedia.org/wiki/Mikhail_Gorbachev)'s speech to the [27th congress](https://en.wikipedia.org/wiki/27th_Congress_of_the_Communist_Party_of_the_Soviet_Union), it was a hard cover book of >100 pages, about the same size as [Arnold](https://en.wikipedia.org/wiki/Vladimir_Arnold)'s "Ordinary differential equations" (and also with red cover), but much much much more boring.

The speech was normally televised. The only exception I know of is the [Brezhnev](https://en.wikipedia.org/wiki/Leonid_Brezhnev)'s speech to the [26th congress](https://en.wikipedia.org/wiki/26th_Congress_of_the_Communist_Party_of_the_Soviet_Union) which he, apparently, was not able to finish reading himself: he started, read for about an hour, then the TV stopped and he was replaced with an assistant for the "live audience" (congress delegates).