I just moved up to 4.9 and I'm finding I can't figure out how to change the size of the Viewport in the workspace. I'm not talking about the resulting image render dimensions, I'm talking about how much of the workspace the Viewport takes up. I like using both sides of the workspace to have the content library on the left and the other parameters (shaping, posing, environment, etc.) on the right open all the time. When I do that part of the Viewport gets covered such that the camera controls, perspective selector, etc. are unreachable unless I close one of the side panels.
I've tried dragging the borders, but that only seems to impact the side panels, not the center Viewport panel. I haven't found the magic item digging around various menus yet either.
I imagine the solution is either totally obvious or maybe you just can't change the size of the viewport. Any answers would be appreciated.