Simple - Take a piece of plywood with you. When it's time to fillet fish put it on the top of your cooler and fillet fish on the boat. If that doesn't work then look for a flat rock on shore and fillet there.
One day the cleaning station will open and we should have a party. This coming week it will be one month since we have been able to fillet fish there.
[NPS had turned the sprayer water on at the cleaning station so you can fillet your fish there and squirt off the fillet table- you just can't grind fish there. You have to dispose of the carcass by burying it, sinking it in the lake, or in the dumpster.]