It surprises me that there should be such confusion about what to do with Pope Francis. The past has already shown what to do, and it does not seem to me that there should be any uncertainty at all.
When Pope Marcellinus violated the First Commandment, the “council” that could be put together (the Church was heavily persecuted then, and transport slow and difficult anyway; therefore, allowances were certainly made) was summoned and, in fact, stood judge on Marcellinus' actions with the famous “judge thyself”: yes, the Pope can't be judged by his bishops, but his actions can create a situation in which he himself will have to admit his guilt (Marcellinus did) or else. There can be no reasonable doubt that, if Marcellinus has refused to judge himself, the bishops would have gotten rid of him by declaring that, with his acts, he had judged himself anyway.
We know from history that another council condemned , though several years after his death, Honorius. We also know that John XXII was obviously threatened with the same fate, but whilst living (meaning for him: the stake).
What should be difficult in this is beyond me.
Pope starts to flip out, Bishops get rid of him. Easy as pie.
Notice here that there is no guarantee that all this succeeds, or succeeds during the Pope's reign. Marcellinus could have been surrounded by cowardly bishops. John XXII could have managed to force his bishops to obedience. Honorius even managed to die a Pope in good standing! Had God abandoned the Church during the pontificate of an obvious heretic? Certainly not! Was the See vacant? Certainly not! Again: was the Pope a Heretic? Most certainly he was!
Shit, Francis, and heretical Popes just happen.
What is there to do, then? Heavens, do you really need to ask? The laity have the duty to denounce the Pope as heretic and the clergy (most of all the Bishops, and firstly among them the Cardinals) have the duty to do the same. In this way, everyone is put in front of his responsibility in front of God.
The Dubia Cardinals have the sacred duty to denounce Amoris Laetitia as heretical and demand from Francis that he puts an end to the confusion. Failing which, they must declare Pope Francis a heretic and call for a convocation of an ecumenical Council that does to him what was done to Marcellinus. This will destroy his credibility by all sincere Catholics, put an end to confusion and draw clear battle lines between those who are right and those who are wrong. This will nuke his papacy whatever happens next.
However, what happens next is fully irrelevant from the point of view of what is to do. You fight Hitler without asking whether you will win. You denounce atrocities irrespective of whether your denunciation will put an end to them or not. You do what is right because it is right, without assurance of the desired outcome.
Francis must be forced to retract his heretical work or be declared a heretic himself so that his pontificate may be officially condemned as heretical for the benefit and admonishment of all present and future generations of Catholics. Whether Francis is then successfully deposed or not is not relevant. What is relevant is that Truth be upheld and heresy condemned.
The Church is indefectible and will survive a trannie Francis II or an incestuous Francis III. You don't have to be worried about that. You have to be worried about what you – and everyone else – will say when asked what you (and they) have done to resist abomination and heresy.
Pope Francis will most likely die in his bed, as the Pope. It is not unlikely that his successors will be every bit as bad as him, and perhaps even smart, which will make things worse.
But your duty, and the duty of the Bishops and Cardinals, is not to act only if assured of victory, but to act because it is the thing to do.
Not difficult, is it?