A Protestant, is possibly/likely baptised, in which case BOD would not apply, but who can know if a Protestant is "unrepentant" when he dies? Who knows the state of any soul entering their eternity? God alone, unless by special revelation.
Cromwell, being a Puritan, was also almost certainly baptised.
Stalin and Hitler were born Catholics and surely received the sacrament of baptism. You definitively exclude the possibility of their conversion, the possibility that they died in God's grace? That is not Catholic. Admittedly, who would want to be in their shoes? But that is beside the point.
The infidel, the pagan? Let it suffice to say, that if they are saved, it is only in and through the Catholic Church. Imagine some pygmy in a rainforest in deepest darkest Africa isolated from all civilization, let alone Christianity. Did God create this soul? Does He have an infinite love for them? Does he not desire the salvation of that soul that He created infinitely? Will He not give them the means to attain the end for which He created them, and which He Himself infinitely desires? Given that the Church teaches BOD, obviously God does save souls without the ordinary means of sacramental baptism. Now if a soul like this, in invincible ignorance, seeks and desires God and wants with all his heart to know and love and obey Him, will God not take this desire, just like He takes BOD, for the reality of Charity and take that soul to rejoice with Him in the blessedness of Heaven? No one is saying it is not rare. No one is denying EENS. God's mercy is infinite. That does not deny His Justice. Any soul, whoever and wherever they may be, that truly seeks God in this life, whether they be Catholic, Protestant, Jєω, Moslem... any soul that seeks God will not be confounded. You judge the exterior. God judges the interior. God looks at the heart.
You perfectly exemplify where a BOD ultimately *always* leads, namely, to even ignorant infidels and pygmies in heaven. Never mind Scripture teaches that to not believe in Christ is a sin, and that to die in that sin condemns them to hell.
In St. Thomas' Catechetical Instruction, he knows nothing of a BOD or of a BOB, he teaches:
"The Nature and Effects of Faith.--The first thing that is necessary for every Christian is faith, without which no one is truly called a faithful Christian.
[1] Faith brings about four good effects. The first is that through faith the soul is united to God, and by it there is between the soul and God a union akin to marriage. "I will espouse thee in faith."
[2] When a man is baptised the first question that is asked him is: "Do you believe in God?"
[3] This is because Baptism is the first Sacrament of faith. Hence, the Lord said: "He that believeth and is baptised shall be saved."
[4]
Baptism without faith is of no value. Indeed, it must be known that no one is acceptable before God unless he have faith. "Without faith it is impossible to please God."[5] St. Augustine explains these words of St.Paul, "All that is not of faith is sin,"[6] in this way: "Where there is no knowledge of the eternal and unchanging Truth, virtue even in the midst of the best moral life is false."
But BODers say the 'desire' for baptism without faith, is of such immeasurably high value that it is all but a dogmatic fact that it saves. The whole idea is altogether absurd.