Isn't that funny, I was just looking on line for the same thing. I discovered I had a pattern already. It's a McCalls M9222. It has a dress, shell, pants and dress and it goes up to a size W30-32. Good luck.
Becky, I saw the video too and I agree, It's just what I was looking for espeacilly pants. But since I can't wear the sizes she has, I found that Butterick has a designer named Connie Crawford who is making the "real" plus sizes. I was really surprised at the sizes she is designing for and they are not hard patterns to follow.