Sorry I should have mentionned, I'm searching for the option for the editor only, for when I'm editing levels in the layout viewport, not in runtime with the game camera is enabled.
I guess it would be something that allows me to move the main white square workspace around a level as my center of zoom in/out.
Otherwise the farther I'm editing from that central (well, upper left really) white square workspace, the more zoomed out I need to be and the smaller the object, etc...
Basically beyond a certain zoom out, when no scrolling bar are displayed, using space+click+drag in the viewport doesn't do anything anymore.