2014 the bay did ice over, but it was deemed too thin (4" at the shoreline) for ice boat racing.
2015 was more significant, at least in my memory. We had the ice boats out there, think we measured 7" off Good Luck Point and Wannamaker Cove. I remember somebody's truck went through the ice off Pine Beach in March.
I guess my subjective definition of "completely freezing over" is thick enough for the ice boats (6")