Looking for ideas on how to Roll up/store 50 amp cord

Roll your cord? No, unless on a reel.
Coil your cord? Yes. Use the over-under method (Utube video it).
Heavy power and multi-conductor cable will get kinks in it if hand rolled.
Always use the shortest length available to prevent voltage line loss.
When over-underwing into a bin, you can shorten the loops to fit.
Over-undering is the same way a cowboy lasso is coiled. A properly over-under coiled rope or cable can be thrown without kinking.