Hi Hedgie Lover
The thing about any hedgehog houses we make is that they are just a structure to a hedgehog, similar to a group of shrub trunks and branches for them to build their nests within. They are expert at building nests and they will be insulated to the amount needed by the hog, so that there is no need for you to add any extra. They do use an enormous amount of material in a nest. I would not put any more bedding in the tunnel. If you want to, leave some nearby outside. If the hog thinks it needs to use more, it will easily find it.
Hogs don’t need to be warm during hibernation, in fact they need to not be too warm. They don’t go to sleep, as such, it’s just that all their bodily functions slow down.
So don’t worry about it too much. Hedgehogs are the experts at what they need and they will find it, if there is suitable material available nearby.
You might like to check out this Hedgehog Street information about hibernation: https://www.hedgehogstreet.org/hibernation-faqs/
