Feeders/Afks should punish you less

So I recently got 100 LP and decided to do my series games. The very first series game I played 2 people rage quit the game and 1 was lagging too badly and was feeding. Now since I basically played a game as a 2v5 I have a loss for my series which I find to be rather unfair to the 2 of us that were just trying to work our way to a higher rank.