If one assumes that the SV position is correct-no valid Pope since 1958, the thing that sticks out is this:
The longer this crisis goes on and the seat is vacant, one will be left to elect and, who is electable the longer this goes on?
What valid priests are left-do they elect out of their ranks, like electing a new abbot? who then could consecrate said man a Bishop?
How does the vetting go, to insure said man is sound and electable?
(and yes, have heard about the Angelica Pope to come, Sts. Peter and Paul flashing light,etc)
This is the boggle some of us have not in the SV opinion...
First of all, not all sedevacantists assume that the vacancy began in 1958. The election of John XXIII is a convenient point in time because the "changes in the Church" seem to be able to be traced to this event. However, until Benedict 16, all of the men elected were undoubtedly valid bishops and could have been popes. I'm not going to get into detailed discussions as to whether they ever validly assumed the papacy but each (other than John Paul 1) made their heresy and/or apostasy so clearly manifest and public at some time that no one (even you) would have described a person who did these things as a "Catholic" unless he were thought to be pope.
Secondly, when a Catholic assumes the bishopric of Rome, if any one of the consecrators is a traditional Catholic bishop, his consecration will be valid. At some point in time we will have a new pope, though it will take some time before he is universally accepted.
What, I think, will be the greatest sign that a true and valid Catholic bishop has assumed the papacy will be that traditional Catholics begin to accept him while the Novus Ordo catholics and, most especially bishops, go into schism.
As I said, the election of a true pope will be a tumultuous time for the Church. I would not be surprised if he's only able to remain in the Vatican because the Swiss Guards protects him. I would not be surprised if nearly all the cardinals declare that they made a mistake and elect an anti-pope as happened once before when the pope returned to Rome.
Whatever happens, it will not be something that only a few people can discern.