I don't know about Sotomayor. If her diabetes is well controlled and she has no major complications, she might stay a while longer.
Ginsburg? Well, she looks like death warmed over.
These justices want to hang on because the job pays well, it isn't all that stressful, they have clerks to do much of the research and they have significant power over us riff-raff. Not about to give it up without a fight.