I forget which saint it was who asked God why He sent souls to Hell, since He was all good. So God told her to pick a soul from Hell and that He'd put him in Heaven. So God did, and the soul cursed and blasphemed because he absolutely hated it there. So the saint asked for Him to at least put him in Purgatory, in part where he didn't suffer as much. He hated that as well, complaining that he was neither here nor there but caught in between. Then God told the soul that He gave him perfect freedom to go wherever he wanted, and he dove right back into hell. Souls in hell are there because they WANT to be there. I am absolutely certain that God would open up the gates of heaven even to the damned if they actually wanted to be there or could want to be there.
I think this is true, but its inconsistent (at least from a probability standpoint) with the kind of rigorous EENS you hold to.
It seems *highly* implausible that there are no souls among the Eastern Orthodox, the Protestants, even non Christian religions, who ultimately, at the end of the day, *would* want Catholicism if they knew it was true and what God wanted.
Granted, I suppose you could fall back on "well we just can't try to fully understand God" but I suspect this may have been why Lefebvre thought as he did about EENS.