It seems to be fairly clear that the bulk of the Numenoreans
were too far gone to reverse their fate. Consider that Tar-Palantir's
efforts failed and that a far more sustained effort, and more committment
by the bulk of the Numenoreans would have been required.
But without Sauron egging on the great majority of the Numenoreans
there would probably have been a slow decline in their "happiness"
and drive toward imperial rule in Middle-earth, which paradoxically could
have led the faithful to slip away from Numenor to northwestern Middle-
earth, setting up a complex geopolitical situation of strong realms of
the Faithful, strong southern enclaves of Numenorean colonies interacting with nativist peoples and elves inland and with Sauron and his lads hovering around.
Numenorean physical and mental decline should eventually sap the strength
of the home island leading to independence movements in their colonies.
(T.A. 1776
)
Which I imagine would bother Sauron less then a Numenorean 2nd invasion
aimed at him around T.A. 1066.