I know EXACTLY what you mean here Darkzombie. Having to go back to the start of the dungeon every time you die and re-kill enemies we have just recently killed, and then to face the same boss again, only discover that his health points have completely filled up again by the time you get back to him…?
I have been having a bit of a grumble about this in a seperate thread. Although mine concerned the Wine Cellar dungeon, I think we are on the same page here. I have suggested that we should either 1) have checkpoints implemented in dungeons, even if only one at the half-way mark and one before the final boss, or 2) that we be allowed to place Bedrolls in dungeons. As an Offline Singleplayer, we can already do this in most dungeons (including the Midnight Grove!) as you will see. However, we should have this option in all of them.
Heres the link if if you would like to either read it or post.