You need a retest of high and the confirmation of downtrend. What if the price keeps sliding down from here, or only bounces half way and resumes the downward movement?
That is what your plan is for - to cover all these "what if's?" But the plan will be useless without the preparations to deploy it.
If a lower limit is to be found up here, then 00-12.5 +/-2 is where I'd expect one to be. If the market opened right now, I would be looking more at 10.5 for a potential LL and 35 UL, but that's me. I also would not be surprised to see price test 78 +/- 2. I do not usually trade before the 9:30 EDT NYC open and have no plans, as yet, to do so today.
Or, you could just close your eyes, hit the sell button, and hope for the best.