The Salvation Threshold: On God's Grace & Redemption

Is there a point where a person becomes morally irredeemable?

Or is there some transcendent mechanism, perhaps more numinous, which is allowed within the life circumstance & heart of even the most degenerate & hardened amongst us?

In a word: Can ANYBODY receive salvation at any time, no matter how far they may have strayed or fallen or how egregiously they may have transgressed?

Or is there a "salvation threshold" that an individual can breach, whereby they have become completely incapable of the humility necessary for true repentance & sanctification?