Hibernation is a bit variable from hog to hog, adults to hoglets and males to females. They do apparently sometimes come out of hibernation and have even been known to make new nests during that time.
However, it is best that you don’t disturb any hog by lifting the lid of a house to check on it. It could disturb it and make it waste some of it’s valuable energy. They have two particular types of energy – one to keep them ticking over during hibernation and the other to enable them to wake up sufficiently afterwards. Both are vitally important to the survival of the hog.
Some hedgehogs don’t hibernate at all and for that reason many people leave food out all winter in case. It is possible that the ones who briefly come out of hibernation may welcome a top up of food and water too. I always leave a source of water out for them all year round, in case.
The end of hibernation can depend, to some extent when the hogs began to hibernate. Usually the males hibernate first and come out of hibernation first – so this can be as early as September and returning in March. The females usually wait until any hoglets have become independant and so are, perhaps a couple of months later (or more if they’ve had late hoglets). Some may not return until April or even May. I find the hoglets tend to disappear last. Hibernation is a very risky time for hedgehogs and some don’t survive – for various reasons. So it is always a worrying time for us hog lovers waiting and hoping that our old friends will return in the Spring.