I found sort of the same solution to being able to access other parts of the map while in edit. Scroll as far to the edge that you can, then place a unit..any type works..I was using scout. You can then scroll further, place another scout when it stops and keep repeating till you can scroll all over the map.
On a huge map I needed 6 or so to do that. Then you can start editing the map, including removing your scouts you placed. Once you have access to the remote areas, you always will.
I covered the entire map with ocean but found that the ice caps remained. So to remove them, you must overwrite them with some type of land then go back and use the Change all plots to ocean if thats what you want or just leave it grass. Thats the only way to remove all the polar areas that I could find.
Then I saved the map as a blank ocean template that I could then modify to whatever. It took me a while, but I'm getting the knack of it. Too many work arounds though to get something pretty simple accomplished.
Sabre21