Well, I guess since it's chicken and not pepperoni or italian sausage, you should be ok counting it as a carb craver. Just make sure you don't go overboard with it... If I were you, I'd ask them to cut it normally (if they'll do that), so you can take the guess work out of how much you're allowed..
Not knowing the dimensions of the squares, I'd say 4, tops...
As for this weekend's BBQ.. Lay off the sauce (BBQ sauce, that is
) and if you're having true BBQ meats rather than hot dogs and hamburgers, try to stay away from fatty pieces..
If you are having burgers and dogs, stay away from the dogs and no cheese on the burgers unless it's "natural", non-processed...
Otherwise, HAVE FUN!!