When you upgrade a website (e.g. the version of silverstripe) do you do something like add an index.php in the root or change the htaccess temporarily to link to a static page indicating you are carrying out maintenance? Is there a simple way to do this with silverstripe?
You shouldn't really upgrade the core on the live site. I also think relying on a module may not work as if core breaks then it'll bring all SilverStripe specific code down with it. You are best using your own maintanence.html file and .htaccess rule (as shown above) than a module.