Ubuntu Servers :: Allow Logins When There Is A Shutdown In Progress?

I've got a server that I just use for backing up and archiving files. Since I don't need access to it often I just keep it powered off. I set up wakeonlan and have port 9 and port 22 forwarded to it.

I travel fairly often, and how its set up now, I can send the magic packet to the connection its on and wakeonlan kicks in and powers up the server. Then I can sftp into and access the files I need and then shut it down again in ssh.

It all works good until there's a power outage. For some reason after a power outage wakeonlan doesn't work.

Here's a workaround for this: I can set the system to automatically power up after a power outage. Problem is, the computer could be on for a week or more, wasting power before I log in and turn it off. So the workaround for that is to put a "deadman's switch" where a script will run at startup that will run "shutdown -q -P +5" which will power off the system after five minutes.

After I run wakeonlan I can ssh in and run "shutdown -c" to cancel that shutdown and still use it. If there's a power outage, once power is restored, the system will start up and then automatically shutdown again and be ready for the next wakeonlan signal I send.

Everything is flawless, except one problem. When "shutdown -q -P +5" executes, it disables all new logins. If I'm fast enough I can ssh in before the shutdown program disables logins, but not always. What I want is a way I can run shutdown without disabling logins.