I would expect many of them to be showing leaves by now, but you may have to scrape away the carpet of autumn leaves in order to find them. If in doubt, dig up slabs of soil from here and there, 'plant' them as they are, and keep your fingers crossed. It must be better than letting the 'dozers churn them to nothingness!
At least you may get seeds if not plants.

You could have a word with Barry Glick - http://www.sunfarm.com/. He may have a better idea what to look for by way of violets in your neck of the woods, though he is somewhat south of you, in West Virginia.

Good luck.

My potted ones are peeping up and my mom's ARE up, but haven't bloomed yet here in SE PA. I'm ready to go a-violet diggin' over at her place very soon!! hee hee