Hi GMATassasin,
While there has not been much clarity on how to use IR scores to measure / predict performance at Bschools and jobs, majority of the schools have ignored or not paid much heed to the IR scores in the last couple of years. Having said that extremely low scores have been seen with some skepticism and especially in the light of QA and VA scores on the GMAT. A good score in QA and VA typically tends to offset a bad outing in 'IR'.
Given the number of students who have given GMAT in the last few years and the IR ranking updates since then, I expect that the schools would start giving 'IR' more consideration in another year or so.
Your score of 1 (0 percentile) is extremely low and basically means that most of the people who have written the exam have scored more than you. Hence, I feel that might raise a few eyebrows in schools you are targeting.
My suggestion would be that you retake GMAT and improve on your IR score, more so given you used to score 4+ in your mocks. This would also give you an opportunity to improve your overall GMAT score to 720+ as there is definitely scope for you to improve your QA and VA scores. Had you received a 3 on the IR, I might not have suggested you to retake, but a score of 1 is too low.
Moreover, in case of multiple attempts, schools generally consider your best scores. So give yourself 2-3 weeks and give it another shot.
All the best!
Cheers,