I'm going to assume you've looked inside the pillow case, down under the edge of the mattress, etc. And since knot spells are generally to tie something up until released, or bind together or hold in place, etc., I'll guess that's the general intent. So, with that said, had you also done a divination before hand to see if doing the spell as intended, ie, in concert with the extreme forces of biggest danged storm in 99 years, was a good idea or over-kill. If not, the cord could have been diverted by any forces you may request to aid your work. I've had it happen, and was grateful to the Powers for interceding and preventing a foul on my part.
If the cat swallowed it, & time will reveal this (e-ew) & as it disintegrates, intervention has delayed the effect (something like burying it) & cancelled the extreme force; but I think knots have to be untied to release the power. If it's destroyed, it's cancelled by intervention. If you find it laying around the house, you can untie the knots at an appropriate time.
Watch your dreams over the next week or so. You may get some indication of how to proceed. If something needs binding so much that you'd metaphorically throw a hurricane at it, the problem may respond to being readdressed.
I have looked EVERYWHERE!
Yes, the spell was intentional during the hurricane for maximum power, it was very important to me. But I didn't do a divination to see if it was overkill. To me, because the subject of the spell couldn't have been more urgent.
I did a knot spell so that the SPELL ITSELF would be binding and never undone, which would be ideal. But now that it's lost or possibly eaten I'm afraid it won't work.
I'll be patient to see if it turns up, but if not, you are right, it will have to be reassessed and readdressed so that I can either try to find it with another spell or possibly try and redo it through other means.
I was wondering also that if it is indeed lost, but still intact, if doing another spell with the same subject would even work.