I want to highlight another possible way to export a single page from Wordpress, without using plugins and without changing anything in post attributes/metadata: it's WP-CLI.

An example:

wp-cli export --post__in=123

this will generate a XML file in current folder containing only the post (or page) with that ID.

For more information consult the command reference here.

There are of course some requirements to use this option:

• access via shell to the DocumentRoot where WordPress is installed
• wp-cli installed on that server (or locally, using the --ssh option)