How big should a humid hide be in comparison to your tortoise? For example for my 4 inch redfoot should the humid hide by just a little bigger than her so she fits snug or does it need to be bigger where she can walk around?
As big as you have room for.
You'll thank yourself later as the tortoise grows.
Dedicate an area and find or create a suitable enclosure and tweak things untill it's just right.
Then sit back and enjoy.