Probably. If there is any movement at all the wax does not rebound and freezing seems like it would only make that worse. Pipes and floors and building tend to move and expand and contract when warming and cooling.Toilets in RVs have rubber rings to compensate for the movement.
I had a toilet at my old house on an uneven floor and no matter what I did it ended up rocking and leaking.
I put in one of these type rubber rings and fixed it with no more worries.
http://www.amazon.com/dp/B005K89RQU/..._843379741_871