Since its all quick disconnects, take some extra and set it in the bottom of the drain tub. Hook it up to the side that goes to your resivoir. Take another line and connect it to the nozzle side and hang it out the window, or out the front door and then run the pump.
Why drag that heavy tub out and disturb the chams?
Looks good. You might want to give the power cables a little more of a 'dip' to create a "drip-loop" so that any water that may trickle down them will fall off into the tub and not find it's way into the plug socket! Just thinking if you do move it around you may not always have such a good dip so that the water won't reach the plug!
I'm guessing you have holes cut out on the pvc bottoms to allow for plant drainage? Why not just place some smaller tupperware containers underneath the holes to catch the water? That way you can easily slide the containers in and out, without having to move your chams cages. Granted it won't hold as much water and will require you to empty it more often, but you may find it an easier solution; it works well for me .