I don't think poorly mated queens should have much effect on over-wintering. Late supercedure this year or early next season is the risk. Soo, depends on the weather for mating this month, whether you count spring drone layers as winter losses or take weak colonies into winter.
The greater risk is going into winter with varroa-ravaged winter bees. Simply assuming apiguard treatment has worked effectively is one area which would likely lead to losses - particularly if the autumn brooding keeps going until December (so the post-apiguard varroa count has quadrupled, at least).
Simply put, strong healthy colonies, with adequate stores and thermal retention will generally survive without any fuss; weak nosemic colonies with high varroa loads and possibly short of stores or in draughty, cold hives will be the ones at most risk.
