I have to agree with the naysayers.
We have eaten there twice with ADR's during very LOWWW crowd times and even then they would not take any walk ups.
Our last trip, the second week of Jan, the parks were very empty and almost no lines at any rides all week, but I think everyone that was there had ADR's.
They were taking no walk ups at La Cellier or Spoodles and Crystal Palace and Chef Mickeys both at 1 1/2 hour waits for walk ups.
I do not think that there is any time that I would chance going without ADR's.
I say make an ADR somewhere else, then keep trying at La Cell. You may have that one in a million luck and get one, but no way I would even think about it without one.
I do know some that have lucked out with an ADR at a booked place by getting the Hotel Guest services to call on the day you want one.
Otherwise, wait until next trip and call La Cell first at your 180+10