Maybe a terrace of hog houses!
The hoglets appear to be sleeping and moving on top of the straw which is not what they need for hibernation. They really need to be surrounded by it! With all those on top of it, it must be getting fairly well flattened. Hopefully they will discover the other hog house – although they might just all move in there!
Not sure what you can do, unless you think they are too small to survive hibernation, other than monitor the situation and if possible provide even more hog houses! I am assuming they are already still coming for supplementary food and water.