Autoarranging Artboards - Illustrator

Go from This...to This

And Some Other Stuff

First, The Other Stuff:

To create an artboard that automatically fits all of the artwork inside of it, go to :

Object>Artboards>Fit to Artwork Bounds. 

As you can see it creates an artboard that just barely fits all the numbers inside of it, automatically.

To resize a specific artboard to fit the artwork in it, select the artboard tool 

[or press Shift+O], then double click on the artboard of your choice.

Now for the Arranging, as Promised 

Click the flyout menu in the artboard panel, and select 

Rearrange Artboards...

This will make a new box appear where you can customize all the aspects of how your artboards will be arranged.

*Make sure that the Move Artwork with Artboard checkbox is checked!

Click OK and BOOM, organized workspace.