After moving Drupal 7 site, adding /user or /?q=user to base URL simply reloads maintenance page I've just moved a Drupal 7 site from Bluehost to Inmotion (by reinstalling the latest core and adding the 'sites' directory from the old server account, then uploading the database). Since the move I can't log in from the browser.

The DNS has transitioned. At the new location Drupal is installed in a subdirectory -- public_html/sub. I've altered the .htaccess file at the level above (public_html/.htaccess) as per these directions https://support.lunarpages.com/knowledge_bases/article/549 so that the site will open there with the base url in the browser.

That does happen, with the base URL currently showing the under maintenance message, just as the site was left. But when I attempt to go to /user or even /?q=user to log in and resolve any last errors from the move, then bring the site back online, I am not given a login form. It simply continues to show the under maintenance message.

I'm guessing this problem is somehow related to .htaccess and/or settings.php, but I can't seem to find the right combo of changes that will allow me to log in. Any suggestions? (I did clear the cache and sessions tables in the DB when this error first occurred, but no help.)
Update your settings.php to this:

$conf['site_offline'] = 0;

From https://www.drupal.org/node/276457#comment-901392