Building config using Interface Options Addons Panel

[Mischback]

I'm trying to make a config using this tutorial.

Works great so far, but I wonder if you are able to scale the actual frame, to have some more space.
The default size is way too small and I have some trouble to bring my options in while keeping a clear overview.

Does anybody know what I have to do to change the size? I'm really sure I saw this in an addon, but can't remember which one.

And I really don't want to build a custom frame, I like it included in the general options.

Any help would be appreciated!