It's a sensible plan, and one that I'm sort of following too.
Historical precedence suggests there is a good chance we'll see -40%, a fair chance that we'll see -50%, and a small chance that we'll see -60%. (But it also suggests there is also a chance that we have already seen the bottom, so best have made use of at least some of your ammo).
If we do reach those depts or even lower, there will be some element of duration about it also, enough time to pull some cash together to plan your next few buying points.
Having a clear plan is key. It doesn't need to be the best plan, just one that emboldens you to action during the window of opportunity.
BTW, I just love this quote from the article:
"A high savings rate acts as a margin of safety."
Nail. Head.