Doubtful.
The Army was broken by the purges and the inclusion of the political commissars at every command level, the Party was cowed by Stalin's more or less random purges and individual deportations/imprisonments, and the entire society was terrified of the NKVD.
The only time that Stalin was vulnerable was immediately after the Nazi invasion. Had there been a real alternative, Stalin might have been overthown then. Once the Party decided that Stalin was the only one who could save the Revolution (and the USSR) from the fascists, that moment of vulnerablity passed.