worst case is if a partially frozen lake blows open, then freezes with broken up ice chunks in it... it will trap air, and the ice chunks will insulate in places and keep the ice from driving down... you will b fine, till you're not...
i know from fishing the river, if you can't drive on it cuz of a rough chunky surface, you shouldn't even walk on it until everything else is really thick... the rough surface will also catch and hold snow instantly, which will make it really sketch till mid winter...
be safe all...