When panning the canvas, make UI 90% Opaque.
When holding spacebar and moving around your entire canvas: instead of cutting off content behind the UI panels, why not decrease the opacity of your UI Panels on the left and right to be about 90%. This way you can at least see what's being overlapped etc while moving. When it's registered that you've stopped moving, the UI flips back to 100% opacity.
Shane G shared this idea