How Plausible is Restoration of Cryonically Preserved People?
Largely implausible, mainly due to damage from freezing. This type of damage even happens when food is frozen (although flash-freezing decreases it).

More feasible approaches for avoiding death would include machine-replacement parts, lab-grown transplants, neural backups, and regenerative gene modifications. I'm surprised no one has considered studying hibernation and how to add similar genes to humans that would enable hibernation.