It takes me 30-50 minutes per queue (average for me is 44). Each match lasts about 13 minutes.

Level 20-21 needed roughly 2400exp.

5-6 hours to level up? Level up at a low level? If all wins at that? I can't imagine level 37-38. If I had to wait 10 minutes per queue, it'd make a substantial difference, and even that's questionable. All that needs to be fixed is the wait times, which would be fixed with the GC unrestriction. Playing at a later time isn't a viable option.