The thing is i don't think you get low priority queue just for one game.
As the FAQ says :
What happens when I leave a game for the first time?
After the game, you will see a pop-up with a LeaverBuster warning. You must follow the prompt on screen in order to queue and play additional games. This does not mean that you've been punished, this is merely a warning. After leaving several games, you'll receive a notification that you've entered the low priority queue.
Ultimately electricity or internet issue are your responsibility, i hope you realize that the low priority queue isn't that big of a punishment, use this time to take care of those issues and look at what you can do to solve them, for example switching from wifi to ethernet is a pretty common thing used to fix constant disconnections issues.
I mean someone leaving a game is ruining the experience for all his teammates, riot can't just let that happening otherwise you'll get people leaving games every time.