I know that at least some of the events depicted in this documentary happened. It is for sure that after WW2 a fleet was sent to Antarctica from the USA.
Beyond that though it is speculation.
There is a lot of evidence to show that many Nazis did escape to South America. Also they certainly had the means to travel to Antarctica, either through some of the large aircraft they created or one of a couple very large submarines that were missing at the end of the war.