It seems a little odd to only offer the admin bar for a page, but the easiest solution I can think of would be to use conditional functions to deregister scripts/styles and create custom template files for this specific page.
Unfortunately, you’ll have to figure out all the styles/scripts that are loaded
add_action('init', 'remove_all_the_things');
function remove_all_the_things() {
if (is_page(123)) {
wp_dequeue_style('main');
wp_dequeue_script('jquery');
// etc
// remove other actions/filters as well
}
}
and you can create a custom header/footer with
header-empty.php
& footer-empty.php
calling get_header('empty');
& get_footer('empty');
in your page template
Reference:
https://codex.wordpress.org/Function_Reference/is_page
https://codex.wordpress.org/Function_Reference/wp_dequeue_script
https://codex.wordpress.org/Function_Reference/wp_dequeue_style
https://codex.wordpress.org/Function_Reference/get_header
https://codex.wordpress.org/Function_Reference/get_footer