The teaching of the Catholic Church is found in the Sacred Deposit of Faith: Tradition and Scripture, as interpreted and taught by the Magisterium. The opinions of Saints, per se, does not equate to Tradition. The Magisterium decides which teachings of Saints are a correct understanding of Tradition and which are not. And the same is true for Scripture.
There is no definitive magisterial teaching asserting that, in the literal sense, few are save and most persons go to Hell. The recent teachings of the Magisterium tend toward the opposite conclusion, that many are saved, even among persons formally outside the Church.
Pope **Saint **John Paul II:
“the followers of other religions can receive God’s grace and be saved by Christ apart from the ordinary means which he has established”
“The universality of salvation means that it is granted not only to those who explicitly believe in Christ and have entered the Church. Since salvation is offered to all, it must be made concretely available to all.”
For this reason the Council, after affirming the centrality of the Paschal Mystery, went on to declare that “this applies not only to Christians but to all people of good will in whose hearts grace is secretly at work. Since Christ died for everyone, and since the ultimate calling of each of us comes from God and is therefore a universal one, we are obliged to hold that the Holy Spirit offers everyone the possibility of sharing in this Paschal Mystery in a manner known to God.”
above quotes are from the encyclical
Redemptoris Missio.
“salvation is accessible in mysterious ways, inasmuch as divine grace is granted to them by virtue of Christ’s redeeming sacrifice, without external membership in the Church, but nonetheless always in relation to her (cf. RM 10). It is a mysterious relationship. It is mysterious for those who receive the grace, because they do not know the Church and sometimes even outwardly reject her.”
[Pope John Paul II, All Salvation Comes through Christ, General Audience, May 31, 1995]
The words of a Saint who is also a Pope, who is teaching under the Magisterium, takes precedence over any number of mere opinions by other Saints.