For me wolves were never an issue. It's just like with everything on Death March. Don't let them hit you and you're fine. Quen before the fight is fine, it allows a mistake, but I don't waste time on it during the fight. Don't let them surround you, as one hit will make you stagger and let the rest of the pack finish you off (there are ways to get rid of the stagger effect, though). Also, I tend to fight during the night as the Towny Owl elixir (was it the name? I've played the game in Polish and Russian recently, and I can't recall the English name) doesn't expire then. And I love all the area effectcs. Igni (igni is waaaaay overpowered in the game, it makes all fights too easy), aard do make me feel sorry for the packs. Yrden works fine, but yrden implies stationary, defensive strategy. I don't like it. I tend to fight actively and take initiative (it's kind of funny when a woolf runs away from me and I have to chase it through half of the woods).
NG+ doesn't seem to be much harder on DM than the non NG+. Due to the choice I have, it's actually easier. I've got all master gear and weapons to choose from, based on situation and quite a few clear potions (was it the name?) if I have to change the setup completely (but I believe, once I reach lv 50 or so, I won't need them anymore, as I'll have all the skills I use at desired level, so I'll be able to simply change the setup).