So I had Morrigan with my when I met Wynne for the first time, and I hadn't read up on the game too much... anyways, Wynne is dead and Morrigan is my healer/CC... am I screwed for this fight?
Nope, I ended up doing the same thing and didn't have a healer for the fight either. My strategy was to have Leilana equipped to be as fire resistant as possible (at that stage of the game, it was with Wade's Drakeskin armor, some salve, etc.) and have her shoot ice arrows and down healing potions whenever necessary. Everyone else was fodder. My main warrior, Zevran, who I never ever used except for that fight because I could pull all of his level up stuff into being a second Archer, and Sten just attacked away till they died (I didn't heal any of them) and Leilana took care of the rest.
I was definitely not expecting her to turn into a dragon though so the first time I fought her, I was caught totally unawares and just about died immediately.