setting minHeight in CollapsingToolbarLayout not having any effect

This one is pretty easy. Just set bottom margin of your Toolbar to whatever space you want to be reserved in the collapsed version.

The reasoning behind this is simple. CollapsingToolbarLayout inherits from FrameLayout which stacks images on top of each other. The only things it takes in account when considering collapsed bounds are toolbar height and its top / bottom margins.

You can set the height to 180dp instead of using minHeight, and then add a TextView into the toolbar to serve as the title.