I have layed and mortared 1/3 of the floor that I am working on. Since this is a weekend project for me,it will be several weeks before the entire floor is layed and mortared. Is it ok for me to wait until I can grout the whole floor, or should I grout each section that I complete as I go?

P.S. Thanks again for your help with the layout. I straddled the center line as you suggested and now have a 9" tile on either end. (Much better than the 2.5" that I started with!)