The replacement token civicrm-user:one-time-login-url not working in Drupal Rules emails
The good news is that it is possible to send an email with a one-time login URL using rules. 

There is an issue on the rules module for exactly this ability: problem with mail and one-time-login-url. A patch has been created for this issue that generates a new action in rules to generate a one-time login URL variable which you can then use to insert into an email. I updated the latest version of the patch to work with the most recent dev version of rules.

You will need to access the Drupal user account details in the rule in order to generate the login.