Thank you for clarifying your post. This makes sense. In normal times there would be a true Catholic priest available, so an out-of-town/jurisdiction priest is not necessary.
Nor, IMO, would there have to be some GREAT crisis in the Church. It could be something as simple as a priest being approached by a potential penitent at an airport, say, someone who hadn't gone to confession in 20 years and who was suddenly inspired by the appearance of the priest, or even if someone were just in a state of sin and didn't anticipate having access to confession for some time (but not someone who just found it convenient that there was a priest there to save them a trip to the local church that afternoon). Canon Law was written during and meant for normal times in the Church, where most Catholics lived within a block of a Catholic church with 5 priests stationed there rotating hearing confessions. But it was never intended to be an impediment to the good of souls, and all Canonists agree that the highest law is the salvation of souls. Once the Church is restored, that kind of thing needs to be made explicit in Canon law, that in circuмstances of just cause (ruling out "inconvenience" of finding a priest with jurisdiction), the Church directly supplies jurisdiction for Confession to all priests, on a per-situation basis, especially if the priest has faculties somewhere in the world, and perhaps for more grave situations, even for priests who don't (perhaps retired, laicized), and in danger of death even schismatics. Canon Law was intended to prevent a free-for-all where
vagus priests could just travel the country on some personal apostolate and intruding on the rightful bishop of a territory. But if approached by the faithful for just cause, they should be explicitly granted jurisdiction by the law itself.
AND, when the Church is restored, there should be a process defined for the potential "heretical pope" problem. No one anticipated a situation where 95% of the Cardinals and 99.5% of all bishops also fell into heresy. Who exactly is supposed to declare Bergoglio deposed? Arian crisis was similar, of course, in that estimates have 97-99% of episcopal sees taken over by the Arians, but the Pope never taught Arianism, despite being very weak on it. So had Liberius become a full-blow Arian, with 97-99% of the episcopal sees under Arian control, the Arians would have seized control of "the Church". That's another reason why the Sisco & Salza analysis is such garbage. According to their logical principles, in that scenario where Liberius would have gone Arian, the Arians would be the "Catholics" and the non-Arians would have been non-Catholics outside the Church. What utter absurdity. Had Liberius gone Arian, those 97% Arian bishop would accuse Liberius of heresy and declare him deposed? It would be laughable if not so tragic. Heck, Arius would have condemned the Conciliar Church as heretical.