So 2 years ago I looked this up and had figured this out. Every time the site was put into maintenance mode it automatically displayed an html page that I created and had sitting in the top level directory. I believe I had made changes to the Bootstrap file.
I recently upgrade my magento version, and whatever I did before got overwritten. I've been searching for an hour and can't find the instructions again, and I don't even remember where the Bootstrap file is. Can anyone help?
PS - I prefer not to do this as an extension. Thanks.
Solved! Go to Solution.