Sorry, I must have explained badly. I don't want the dock smaller, I want it bigger.
If I've only got one window open, the dock is only one icon wide (well, it's a bit wider, but there's only room for one icon in it), because the width of the dock is determined by the number of icons. But I want it wider than that. Even if there's only one icon in the dock, I'd like the dock to be half the screen wide.
The way it happens at the moment, if there's only one icon in the dock, I have to move my mouse cursor to the top-center of the desktop to bring the dock out of autohide.
I want to make it so I can move my mouse almost anywhere along the top of the desktop to bring the dock out of autohide, even if there's only one icon in it.
I've managed to do this by putting 'invisible' items in the dock (I've created flyout menus with no name, no entries and a blank icon), but my open windows are always either on the left or on the right, and I want them in the center. Is this possible?