Rank is unplayable for solo Q. I don't have a premade team.

As someone who is mostly a solo player I do not find this statement to be true. It is very much playable and winnable. I solo ranked a lot and do just fine. The key is stop doing what your team thinks is the smart play and sit back and think of the actual smartest play. Such as 2 push a bad push which you know is not winnable so you chill back playing yourself. While it is a team game where you get better results being with friends it still is possible for a solo player of all skill ranges. It's a matter of do I do what my team does with me knowing that is a bad idea or play yourself and be safe. 

As an example yesterday I was in ranked I see my 2 teammates who were a duo push 2 teams and died. I sat back poking and healing as needed to be told dude this is not hide and seek. Where I responded sorry I'm going to play this smart and safe to know I will kill these 2 teams. As I said that they left the game instantly without even being timed out. I ended up winning that game for 331 rp because I played the way I knew would be the best play. At that point those 2 were my mirage decoys.