Given how there was a lack of privacy and a world in which the subjective was suppressed in the name of the external, Winston's actions speak to a world outside of Big Brother's control.  Winston's actions are all in the name of the private.  Being able to carry on his affairs with Julia, envisioning a world of private emotions and memories, and developing writing and communication that existed outside of the world of the external are all examples of this subjective reality are all actions that Winston takes in order to affirm the right of the private to exists in the world of Big Brother.

Whether his actions were meaningful could be heavily debated.  In terms of significance in overthrowing Big Brother, his actions are not very meaningful.  He is forced to recant and is forced to abandon his beliefs.  He is left as a gutted shell of what he once was and Big Brother's power continues unabated.  Yet, in a larger sense, Winston's actions speak to how governments will not be able to fully silence the voices of dissent.  It might be a rather long time before it happens, but governments will be forced to reckon with the citizens' voices.  The validation of private and public voice is something that Winston embodies in his dissent against Big Brother and is something that ends up becoming quite meaningful in reflecting about the work.  We still speak of Winston's actions, which indicates that on, some level, they possess relevance and meaning.