Hibernation timing is not fully understood but it does not relate solely to temperature. Other factors, i.e. availability of natural food, etc. are also involved. Some male hogs will hibernate as early as September.
It’s possible that human activity i.e. feeding hogs may have some impact. But that also may be keeping more hogs alive i.e. late hoglets and those that choose not to hibernate at all (often also hoglets).
Hogs are known to emerge at time/s during hibernation and may even make new nests,
It’s really important to leave water available for the hogs all day every day, including during normal hibernation time.
Good luck to all hogs for a successful hibernation time – however they choose to spend it.