This quest definitely blind-sided me when I attempted it at ~5th level right after Caed Nua.
I came back at level 12 on Hard mode and *still* had a very challenging experience, but not a negative one. It was a lot of fun, despite the frustrations, I was usually managed to make it through 2-3 groups at a time before needing to rest and recoup. Most of the other combats up to this point, with exception to the Sky Dragon, were easy enough to rarely require per-day abilities or consumables, so having a super tough section feels like the Emerald Weapon or Omega Weapon of the game (though perhaps not quite *THAT* hard).
When you reach Commander Baelorin and ask him to offer you work, he retorts how absurd that would be given how your group just slaughtered so many of his men. Has anybody tried sneaking all the way up to him and *then* asking for work, without having killed a single one of his soldiers?