My friends and I have been playing and struggling through the game, but when we reached the Elite 4 we just had to give up completely. At least with all the other battles we could just throw ourselves against the trainers, defeat a couple of their pokemon each time until we levelled enough to win, but we can't even do that against the elite 4 because we need to wait 40 minutes between attempts. None of us could be bothered doing the hours of grinding it would take to even begin to attempt it otherwise so we were forced to give up and just go to the next region.
So why is there a time limit on the elite 4? I could maybe understand it for victories if it gives you money or something, but all it would mean for us is that we'd have one attempt and then play a different game for 40 minutes while waiting for our next attempt.