You could force a style on the node that you clear out the entirety of the PAGE_CONTAINER except what is necessary for displaying the content (I don't know it off the top of my head) and create your page. However, it may be easier just to use a .html file.
In case you use the widget framework, you can add a widget page in the node tree, add a HTML widget and tick the box "Break out of content container" (but header and menu will still be shown).