If hive has brood over winter here, it will surely die. Some strains have no sence of wintering. Also if brood hatches at autumn too late, hive is in danger. If you give too long feeding at autumn, bees starts to raise brood.
Hive seems very big at winter if it has no winter ball.
This winter I have a hive, which has been active all the time. 2 weeks ago I weighed with hand how much they have sugar. Hive was really light. I took a box, and put there 20 lbs capped sugar frames and the rest uncapped. Temperature was 14 F. Also I gived one frame which had plenty of pollen.
That hive seems very big because it is not in the ball. I have some queens whic are imported from Italy last summer. It may be that origin.
Something happens every winter. I have 20% extra hives to repair my "unfortune". Bees are many, and nobody can succeed 100%.
But surely you must study, what to do to hives at late summer and what is dangerous to bees. When late autumn begins, nothing positive is to be done. I have read this forum, and I have seen a lot of mistakes. Sorry, often you give bad advices to each other.
I have paid my lessons many times. It is normal. But change the feeding system.