I think you are probably right about some people giving up feeding too early. Sometimes hoglets appear a while after all the adults have gone to hibernate. I don’t think it is a bad idea to leave food out all winter at all. Hogs sometimes wake up during hibernation and might welcome a bite to eat and I always leave water out all the time. Also, one year, there was a hoglet here who had hibernated but was obviously too small and came out of hibernation early. Luckily I saw him, and managed to rescue the little chap. But I, also, didn’t want people to think that the little ones would just keep coming to feed if there was food there, because some just don’t and if they are to survive need rescuing.
I have got a bit of a problem this year, that a cat has appeared who eats food which cats are not normally interested in – there’s always one! I was then putting the food in the (I thought, cat proof) feeding box, but not only did the cat manage to get in, but then a hoglet decided to build a nest in there. So that has completely foiled my plan. Now I am spreading the food out a bit more and putting some long grasses lightly over the top. The current remaining hoglet seems to manage, but I hoped the cat might be put off. Only time will tell!