I use a heavy duty plastic storage box like this and also use it to store my surge protector and the chain & padlock that I use to protect the surge protector from walking off. Then, it slides in the side compartment with my two smaller plastic bins on top (those two contain my fresh water hose and cable/satellite coaxial wires).
This is what I did with mine....mounted a 5 gallon bucket inside a muck bucket. I drilled a hole in the side near the bottom for the RV end to come out and coiled the rest of the cord around the bucket. I only have to uncoil the amount needed and the rest stays in the muck bucket. The rope handles on the muck bucket make it easy to handle and I store all my adapters in the lidded 5 gallon bucket. I did drill some holes in the bottom to let any rain water drain.
It works fine with a 50 amp cord. I hook the male end under one of the u shaped pieces. I then feed the cord with one hand and crank with the other. I have even kept a rag in my feed hand to wipe the snow off, so it does work fine in the cold too. I would post a picture of it installed, but I would have to climb over a 5 foot snow drift to get to it.