I'll go one further and say that they don't have the Catholic faith. And I say this because their entire position revolves around maintaining the erroneous position of Lefebvre, who only held the position that he did because things weren't as clear then as they are now.
I disagree with your characterization of Archbishop Lefebvre's position. This particular articulation of R&R is decidedly NOT what Archbishop Lefebvre held. He disagrees with their major premise that the Catholic Church and the Papacy could become this corrupt. I'll find the speech he gave on that matter (I transcribed it from audio at one point here). +Lefebvre was open to sedevacantism and considered it a real possibility. He merely held back from openly declaring the See vacant out of deference to the Church's authority. That is in fact a legitimate criticism of SVism, that your average Aunt Helen Catholic is in no position to declare the See vacant, nor is a simple priest, and arguably even a single bishop. Archbishop Lefebvre kept saying that SVism is possible and could very well one day by "confirmed by the Church." So his reasoning was more along the lines of: "This is merely my personal opinion but I don't really have the authority to settle the matter." Archbishop Lefebvre repeatedly stated that the Conciliar Church lacks the Marks of the Holy Catholic Church, i.e. that it's a new religion, and that those marks were with the Traditional Catholics. That too is a point that this cadre of R&R deny.
Unfortunately, the hesitation of Archbishop Lefebvre did ultimately morph into this modern notion of R&R that is not recognizable as Catholic, but it's not a position that he himself held, despite the claims of these R&Rers themselves, always claiming that they are the true followers of +Lefebvre. They're not.