I was given some rather depressing tubers last fall, very shriveled and rubbery!! Still, I managed to prep them for storage and some of them have produced some very healthy cuttings for me... I had about 15 tubers, I had 4 survive, now have 20 rooted cuttings / plants!!

So I know first hand that shriveled does not mean hopeless!

Considering the time of year, I would perhaps treat them with an anti fungal / perhaps put them in a 10% bleach bath for 20 minutes, then pot them up and allow them to start growing!! Even if they are kept indoors on a (south facing preferably) window ledge, they should be fine. Don't plant them out too early though! Even one night of freezing temps will kill them. I learned that this year too the hard way with my store bought tubers!!