Sooo I'm Quinn Ashheart, currently level 47 with the quest to duel Cyrus prior to entering DS. I'm this far ahead because I'm doing Wintertusk. So any of you struggling with DS, go back and do Grizzleheim and Wintertusk. I expect to be level 50 by the end of this, as I'm 3/4s of the way done and almost level 48 .
I do the side quests as well, but I don't bother finishing Grizzleheim before starting DS. DS is not that tough compared to the 2 big boss fights in GH (Jotun and the 4 Ravens?).
Anyway, it's good to hit 48 after you start DS so you can do your spell quest. The L48 spells are a big boost for most of the schools.