Well, if you try design, slide size and customize slide you can input the dimensions of the screen of an ipad.
So, I "customized" a slide, made a background and a couple images and emailed it to myself. I was able to open the email on power point ipad and expand the customized slide to fit the screen snuggly.
This was not perfect because I had to expand the "customized slide" with my fingers. Not sure how "customized" it all was.