Suggestion: A cool way to stave off demotion

I recently played a game that ended in a loss and a subsequent rank demotion (because my jungler int'd and stopped playing around lvl 11), where I recieved an "S+" for my gameplay. How frustrating to get demoted when you perform so well!

I was thinking, wouldn't it be cool if, when you are hovering on a demotion, receiving an S would result in no LP loss? It would certainly make those games more exciting - where currently they are the kinds of games that summon up dread and nervousness when we are trying to climb.