No. It remains trivial. Hit points for monsters at 5th-8th level are averaging 60-120. By the time you run the number over the long haul to 1000 hit points of damage, that will be spread out over 500+ monsters with 50,000+ hit points between them. You're still only going to be doing a few points of damage extra.
Against the same creature sure, but do it 8 times against 8 different creatures and you haven't saved squat. You MAY have gotten lucky and dropped something to 0 instead of 1, but that's rare.