This is so unusual it is hard to guess what you should do. I think you want to stop the roots from continuing to grow, I think I would put them in a dark, dry place and see what happens. If they continue to grow now you likely will have plants that can't be grown outside because of winter climates. I think keeping them in a plastic bag, with no air circulation, is probably not a good long term solution. I wish I could be of more help.

I would let them grow as long as possible to store energy in the bulbs for dormancy. A year without growing will hurt them in the long run. I did that with caladiums one year - missed a pot on the top shelf so by the time I noticed it in late fall - the bulbs were so shriveled up that there wasn't much left to save them.