ARAM idea to be less affected by leavers

We have 2 things that we hate when someone leaves: wasting time to get into a game and losing a good champion/team comp. One of the reasons for people to leave is getting another champion as they enter the queue again, but maybe the system should store the last champion that you got in ARAM until you play a game, so you can keep the good champion that you got random instead playing with something you don't like because you lost good champions because of people leaving before. Also this will make harder to people leaving games to get another champion because they will know they can't get another one just by leaving the queue. Anyone that plays ARAM a lot knows that you have to change masteries/runes like 2 times before playing because someone leaves and you get another champion.