vaughn, first of, the size right now is going to be the issue. Look back at nobodies post and you will see at the bottom of it
even if it means have a few pixels more than the limits of width.
So he did say, going slightly wider would be OK, if you needed it. When I clarified this for you, I did explain that with the size of the map you will have to justify all pixels.
You posted that you would like the size to go up to 880-900. I miss read that as 800/900. What I believed to be nobodies guide for you. Wider, not taller. My mistake and I apologise to you for this.
Your current draft though is 1024/935. At this size, I doubt you will be able to. Not only is this taller, but also a lot wider than what you had posted.
Get the map down as much as you can but 800 in height is what you are looking for as a max. Do not worry about the width so much. But if you can get that to the 900 like you said, then all good IMO.