I recently had an episode where I put a site into maintenance mode to perform a security upgrade and forgot to go live again afterwards, resulting in almost a day of downtime before I caught the error.
I thought I could set up a rule to send me an e-mail whenever cron runs if it detects that the site is in maintenance mode, but I don't think that's going to work because cron can't execute when maintenance mode is on. A preliminary test seems to confirm that. I put the site in maintenance mode, attempted to run cron manually, and no e-mail was generated.
Is there another module or method I could use to send myself a reminder so this won't happen again?