I sharpen "stuff" as a side job. Included in that list of "stuff" is old straight razors. (Restore, hone, and use 'em) Yes, grinding/sanding will remove good metal along with the rust but you have to remove enough material (even if it's good) to get "PAST" the deepest rust. Sometimes on edges the blade will look good to the naked eye but under a cheap $10 microscope from Radio Shack it looks like swiss cheese. If the swiss cheese is there you've got to go past it.
They may come back nicely, or they may be "eatin through". Just depends. My *guess* without seeing them is that they'll be good to go if it was just one winter.