paulF got his post in while I was composing mine!
-- basically the same answers:
I believe they are OK as long as the ground -- and the potatoes -- have not frozen.
When you grow them you realize the fallacy of "perfect looking produce" -- I actually look at them askance now at the store, wondering just what chemicals (pesticides andfungicides) they used to keep them looking that good.
Anyway -- peel thick and cut away and discard any green skin and areas under the skin. Usually ony parts that were exposed to the sun -- in sufficiently covered with soil and/or mulch so try to be more diligent next time -- will turn green. If entire small potato or very significant area have been exposed, I do set them aside or toss them in the compost just in case. (if discovered close to planting time in spring, then I'll attempt to use it for seed potato).
Holes -- I have serious wireworms problems so potatoes left in the ground too long after the tops die down can be pretty badly affected. Do try to dig them up right away and sometimes even harvest them smaller than they can get if given a little more time.
For the ones that have been "invaded", I prefer to chase down the tunnels with a knife, cut away and discard affected portions, and try to salvage what I can of the potato since the wireworms ONLY affect the portion that they have tunneled (unless spoilage have been introduced). Smaller pieces can go in soups or mashed or hash browned (use the ones with holes in them first for these kinds of recipes in case the worms are still in them). If I can't get a decent whole sized potatoes to bake, I just cut them all into similar sized chunks and make oven roasted potatoes.