Well, that won’t be the Catholic church anymore then. That’s easy. There will always be a faithful remnant, even if they don’t have the pretty buildings or the money.
If the conciliar church decides next year to ordain women, and the following decade to declare homosexuality no longer a sin, then maybe The Remnant are the current sedevacantists who claim that John XXIII, etc. were not real Popes.
Unless you believe its OK to have a series of heretical popes who will provide a link to a true pope somewhere down the line and that somehow kinda sorta provides just enough Apostolic Succession to satisfy the doctrine.