I'm sorry, but you have two options:
1) To believe that Russia was consecrated to the Immaculate Heart of Mary in 1984.
2) That Russia has yet to be consecrated.
If your a sedevacantist, then it is number 2.
If Russia has yet to be consecrated then, um, where is the Pope? Hello? It will be late, but it won't be never.
Fatima proves sedevacantism as wrong.
There are perpetual successors.
If we will have perpetual successors then there are perpetual successors.
If there is not a successor right now then there will be one, and your sedevacantist Bishops, I can assure you, they are not electing anyone. It's a dead end, waste of time. Francis is the Pope. All outside of his fold are schismatics. The bell tolls. All outside the fold will perish.
Our Lady of Fatima, pray for us who are Faithful to thee.