UI Canvas is very small in designer

I have changed the pixel units from 100 to 1 in order to make my 2d game fit nice to 1080p resolution. However when I add a Canvas to my scene it renders it much smaller than the actual scene (about 1/8th the size) and it is locked so that I can't drag it larger or move it position. When the game is running the canvas is indeed the correct size but the tiny designer size makes it very difficult to arrange the elements correctly.

You can see the canvas within the highlighted area. What is going on?