...The very concept of this plan is that if step 1 fails, we'll just lose a few days and be somewhat embarassed.
Unless you mean that there is a chance the cllogging itself will fail, which... we had no indication that it would be that hard or dangerous?
The only reasonable way for the clogging to fail is explosively. We are messing with more than enough power to kill ourselves with only the most basic understanding of how this works. By the same token the odds that we turn off the power and the ritual somehow keeps working does not seem at all likely The Chaos Sorcerer would not be drawing that power in if they did not need it.