As they say: anything is possible. The problem in addressing a question like this is that time does not exist in Purgatory in the sense that it does on Earth. Purgatory is not a physical location within our physical universe, therefore the very concept of time as we know it cannot be truly applied to it.
Souls remain in Purgatory until they are properly cleansed to truly be in, and enjoy, the presence of the Beatific Vision. Time, in a sense, is irrelevant is Purgatory.
