Well, if you planted the "annual" kind, Imperial Star, and they had enough exposure to cold in the seedling stage (4 to 6 leaves, about 10 nights under 50 degrees) you could get a fine crop.

If you planted Green Globe or most other kinds, you may be out of luck. I have had success overwintering the roots in a deep pit below the frost line packed with dry inert material. If you do this, dig them as late as possible just before killing freezing temps (upper teens) trim the foliage and treat with fungicide. Also, be sure to throw the rodent bait in the pit, or there may be nothing to dig up in the spring if voles find the roots. You may try that strategy if nothing else.

Finally, if it's early fall and looks like nothing is happening flower-wise, your other option is to tie the foliage up in twine and paper and blanch it then use like cardoon. A little stringier, but the inner blanched stalks pretty much taste the same.

Hmmm, looks like I chose badly for this years trial crop; I planted the Green Globe; at present the plants have 2 leaves each. I suppose I'll leave them in place for a time, but will likely replace them with something else once the rest of the garden is planted.
Thanks for your advice! Next year I'll give Imperial Star a shot.