For the sake of anyone interested in the answer to this question, I am posting here the following answer that I received in the WordPress.org support forums.
leejosepho graciously provided the following answer:
Yes, that is possible. Save ‘http://dem0site.net‘ in both boxes at Dashboard > Settings > General, then cPanel-assign and -point your domain to public_html and use this htaccess to redirect it to ‘wp-org-01’ (or wherever):
# .htaccess main domain to subdirectory redirect
# Do not change this line.
RewriteEngine on
# Change example.com to be your main domain.
RewriteCond %{HTTP_HOST} ^(www.)?example.com$
# Change 'subdirectory' to be the directory you will use for your main domain.
RewriteCond %{REQUEST_URI} !^/subdirectory/
# Don't change the following two lines.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# Change 'subdirectory' to be the directory you will use for your main domain.
RewriteRule ^(.*)$ /subdirectory/$1
# Change example.com to be your main domain again.
# Change 'subdirectory' to be the directory you will use for your main domain
# followed by / then the main file for your site, index.php, index.html, etc.
RewriteCond %{HTTP_HOST} ^(www.)?example.com$
#RewriteRule ^(/)?$ subdirectory/index.html [L]
## index.php for WordPress
RewriteRule ^(/)?$ subdirectory/index.php [L]
Visitors to your Web site will not be able to tell that your main domain is using a subdirectory, they will still see the Web site address as http://www.example.com/…
https://my.bluehost.com/cgi/help/347#redirect