No. At death human beings make their definitive choice for or against God, so their eternal destinations are permanent. If they choose against God, they go to hell; if they choose for God, they go to heaven or to purgatory (from which they will be eventually released into heaven). While it is true that there is free will in heaven, that free will won’t allow a saint to do what will then be impossible for him to do (i.e., reject God). Analogously, in this life we also have free will but free will doesn’t allow us to do what is impossible for human beings to do unassisted, such as to fly or to breathe underwater without support technology.
