I'd probably guess ON AVERAGE 8' to 11' with room for exceptions.
The big scrubs are the Kinghorni from Australia. Similar to the dwarf and super dwarf reticulated pythons, there are smaller localities of Amethystine python.
I've seen a bit of conflicting information published as to whether or not the males or females get larger. Some of the reading I've done indicates, at least in the wild, males are larger due to male/male combat which is similar to certain species of carpet python that engage in that same behavior. However, captivity often/almost always, changes things. Having that in mind females frequently end up at least equal in size if not larger than males.
Unfortunately I have not read enough in-depth on these as I ended up taking the retic route.