I remember on one of the other threads that Fr. Cekada was quoted as basing his belief that non-Catholics could be saved on the idea that we would have to conclude that God was cruel if the vast majority of the human race is non-Catholic and destined for hell. I hope I'm not exaggerating his position. I think that was the general gist of it. In any case, I offer this quote from
The Imitation of Christ as an answer to that concern:
Not Searching Into High Matters Nor Into the Secret Judgments of God
Christ:
Son, see thou dispute not of high matters, nor of the hidden judgments of God; why this man is left thus, and this other is raised to so great a grace, or why this person is so much afflicted and that other so highly exalted.
These things are above the reach of man, neither can any reason or discourse penetrate into the judgments of God.
When, therefore, the enemy suggests to thee such things as these, or thou hearest curious men inquiring into them, answer with the prophet: "Thou art just, O Lord, and Thy judgment is right." -- Ps. CXVIII. 137.
And again: "The judgments of the Lord are true, justified in themselves." -- Ps. XVIII. 10.
My judgments are to be feared, not to be searched into; for they are incomprehensible to human understanding. -- Rom. XI. 23.
...
I foreknew My beloved ones before the creation; I chose them out of the world; they did not first choose Me. -- John XV. 16.
My Imitation of Christ, Thomas a Kempis, (c) 1982, Confraternity of the Precious Blood, Book Three, Chapter 58, p. 368.
I don't think concern for the salvation of those who died outside the Church should be the foundation of any Catholic theology. If we can't find support for it in Sacred Scripture nor in the tradition of the Church, theological propositions should be immediately ruled out. And we find nothing in Sacred Scripture nor in the tradition of the Church to support salvation for non-Catholics. Instead, we find that 3 times it was clearly and explicitly defined that those who die outside the Church are damned. No need to search into why that is. We can just accept that all of Our Lord's judgments are true and just.