In the past half a year or so, I've never lost to any power wb 1v1 on cele druid. I either win or they end up running away when low (of course I can't catch them then). As for cele wb, I've had one or two neverending fights, the rest I won. You need to predict the wb's burst and chain dodges/evade skills then. For power WBs, they open with a port in, burst with their F1, whirling light, sword skills, then swap to greatsword and so on. You do not want to trade damage with them during the initial burst. Just chain dodges and evades. If you get hit by sword 5 immob, lightning reflexes as they'll for sure burst. In fact, don't be afraid to use Lightning Reflexes or Protect Me even when you are not CC-ed, because power WBs don't have hard CCs. Once they're done with their initial burst, you can counter damage them. They cannot outsustain you, and once their elite has been used, they will die or run away.
Willbenders are a noob stompers, but there are lots of builds that deals with it. Everyone always underestimates its initial burst, which also does decent AOE. So when one ports into the midst of three inexperienced players, they think they have the upperhand, try to trade damage, and get farmed. That is how you get those wb 1v5 montages.