Seraphim,
I do not consider myself a "Feenyite"-hate the labels-Lefebvrites, etc. Those people play God by saying the man died so he lost his soul.
It's midnight and I just pulled out my books on the canons and decrees and the catechism of the Council of Trent. Read over pages 36-46 on canons and decrees. I don't have time tonight to read through both books. This is also my understanding from a theologian and priests.
I'm a little confused by the way the question is phrased. If as the Council says we are justified by the waters of Baptism, it only stands to reason that we as adults must be free from mortal sin in order to be saved. We have to work out our salvation as St. Paul says. Yes, if you die in a state of justification or sanctifying grace - no mortal sin- yes you could obtain salvation. My four month old baby died - received Baptism and Confirmation. She went straight to heaven. But we, as adults, must die with no mortal sin or insufficiently repented mortal sin. Please write again, as we are all searching for the truth. God bless