Yes, a 4-6 hour "main report" of the party leader to the congress was the norm throughout the time when the CPSU was in power.
I remember having to study the Gorbachev's speech to the 26th congress, it was a hard cover book of >100 pages, about the same size as 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's speech to the 25th congress which he, apparently, was not able to finish reading himself: he started, read for ~hour, then the TV stopped and he was replaced with an assistant for the "live audience" (congress delegates).