What lack of physical connectivity???
You can connect the iPad to the computer via a physical USB cable, and use iTunes to sync the Photos.
A word of warning though: The iPad is not designed to manage large quantities of files in large folder hierarchies, even photos.
While the Photo Library will handle one level of folders, it will not handle subsequent levels, so you may end up with a barrage of photos, that are unable to be sorted in any meaningful way.
I think you should research the capabilities of an iPad a bit more before doing what you plan on doing.
An iPad is not a computer it cannot do what a computer does, and is not designed to easily manage that volume of photos. It has no file system like you may be accustomed to with a computer.
It will be a nightmare to manage that amount of photo files on the iPad.