“Only the College of Cardinals can elect a pope”
The College of Cardinals didn’t exist for the first 800 years of the Church’s existence and they were not the sole electors of the pope until the 12th century. Clearly it is not by Divine law/institution that they are so now. So it is by the Church’s disciplinary law that only the Cardinals can elect the pope. But a disciplinary law has no force in cases where necessity dictates an act contrary to the law. e.g. exceeding the speed limit to rush an injured person to the hospital.
On the other hand, that the hierarchy is solely responsible for the election of the pope is by Divine institution. So that law can not be violated under any circumstances.
As you mentioned, and no one would disagree, an imperfect General Council can elect a pope. But you also say that only the jurisdictional hierarchy can convoke a General Council. Can you provide a reference for that? Not that I have never heard that before but I have never seen a pre-Vatican 2 reference for it.
It certainly isn’t required that the electors of the pope must have ordinary jurisdiction because otherwise how is it that the pope was elected in the past by the local clergy of Rome?
“as we know that it is impossible that the Church is left without possible electors of the [Pope].”
Yes because the Church is a perfect society. And a perfect society contains within itself everything necessary to fulfill its mission. But the Novus Ordo is not within the Church. So the notion that the legitimate electors are non-Catholic members of the Vatican 2 sect would place the electors (necessary for the continuation of the Church) outside the Church. The material designation wouldn’t put them inside the Church. Because a manifest heretic is outside the Church.
When I use the term Roman clergy I mean to include all the members (clerics) of the local diocese of Rome including the Cardinals, the auxiliary bishops, the priests, deacons, subdeacons, porters, etc as defined by the canon which you quoted.
You asked who can reverse disciplinary law? In cases of necessity a disciplinary law does not bind and the authority to elect the pope devolves to the highest existing authority in the hierarchy of the Church. These types of scenarios were contemplated by pre-Vatican 2 theologians and as far as I know I’m not proposing a novel point of view. Maybe it’s not a popular view but I didn’t make anything up. I’m basing my view on what pre-Vatican 2 theologians have written.
Finally, I disagree that there are no traditional Catholic clerics in Rome. I’m sure Fr Abramovitz knows better than I. Msgr Fenton and Msgr Van Noort both speculated about the possibility that a nuclear war could wipe out whole dioceses and even possibly all of them except the Roman See. It has been asserted by many theologians that the Roman See will always have at least some faithful living there or at least associated with the See even if they might be in exile. Of course it is dogma that the Holy See will never fail but to what level it can be reduced is not clear.