Several theologians comment that the Catholic Church is a perfect society, which means it has all of the tools necessary for its preservation. This would include the election of a Pope here and now.
Billot: “But the election of the supreme bishop pertains without doubt to the order of the universal Church.
“Let us now investigate, nevertheless, how the law would apply if perchance an extraordinary situation were to arise in which it was necessary to proceed to the election of a pontiff while it was no longer possible to comply with the conditions determined by previous pontifical law; as some think was the case at the time of the Great Schism in the election of Martin V.
“Well, once we grant the occurrence of such circumstances, it is to be admitted without difficulty that the power of election would devolve upon a general council. For the natural law itself prescribes that in such cases the attribute of a superior power descends, by way of devolution, to the power immediately below insofar as it is indispensably necessary for the survival of the society and for the avoidance of the tribulations of extreme lack. ‘In case of doubt, however (e.g. when it is unknown if someone be a true cardinal or when the pope is dead or uncertain, as seems to have happened at the time of the Great Schism which began under Urban VI), it is to be affirmed that the power to apply the papacy to a person (the due requirements having been complied with) resides in the Church of God. And then by way of devolution it is seen that this power descends to the universal Church, since the electors determined by the pope do not exist’ (Cajetan, ibidem). This, I say, is understood without difficulty if the occurrence of the case be admitted.”
Francisco de Vitoria (1480-1546): “If by any calamity, war or plague, all Cardinals would be lacking, we cannot doubt that the Church could provide for herself a Holy Father. Hence such an election should be carried by all the Church and not by any particular Church. And this is because that power is common and it concerns the whole Church. So it must be the duty of the whole Church. (De Potestate Ecclesiae)
Charles Journet in The Church of the Word Incarnate refers to Cardinal Cajetan, who appears to be the common source of all canonists opinions: In whom does the power to elect the Pope reside? The Pope can settle who the electors shall be, and change and limit in this way the mode of election. In a case where the settled conditions of validity have become inapplicable, the task of determining new ones falls to the Church by devolution, this last word being taken, not in the strict sense, but in the wide sense, signifying all transmission, even to an inferior.’” (Charles Journet, from Cardinal Cajetan, in his ‘Apologia’, Chap. 13, no. 745 fl.)
“A Council…acting independently of the vicar of Christ…is unthinkable in the constitution of the Church…Such assemblies have only taken place in times of great constitutional disturbances, when either there was no pope or the rightful pope was indistinguishable from anti-popes. In such abnormal times, the safety of the Church becomes the supreme law, and the first duty of the flock is to find a new shepherd, under whose direction the existing evils may be remedied.” (Catholic Encyclopedia, Vol. IV, Councils; Rev. J. Wilhem;)