Hello @pomilo,
You might want to check this out: Why is my page not full width on the frontend?
The way you describe is definitely possible, but I would recommend keeping your page content within the page item itself rather than creating a template for every page you create.
I usually go with creating a full width blank page with a Post Content block that I can then apply to any type of post type (post, page, or more specifically if necessary) from the Cwicly Themer (Themer - Documentation) conditions.
Hope that clears things up a little.