The limit was mistakenly set low; the problem has been fixed.
4pm We’ve opened a ticket with Google and will send an update when we have a resolution. If you try to upload an item to a Google site, you’ll receive this error message: “Unable to upload file (filename.jpg) because the site has exceeded its file upload quota.” You can still add and edit pages.
To: Google site users
From, more info: Veronica Brandstrader, LTS, x2171