Hi Adam,
An interesting question with a lot of interesting answers as well. I've seen both multitenant and big single Moodle implementations in universities I've worked with.
There are a lot things to consider before deciding in favor of one or the other:
- How's your organization's application administration set up?
- Do you want to host on-premise or in the cloud?
- Does Moodle have to be set up to interface with a Student Information System, an Identity Provider or external authentication platform?
- Does every department need a specific configuration, or is most of this covered in one general config?
- Do you need to interface with tools like TurnItIn or similar for plagiarism detection?
- ...
Setting up connectionsfor multiple Moodles to a SIS, to authentication, to an IDP or an external service like TurnItIn may not always be possible and will most definitely increase your workload in configuration and troubleshooting.
In that sense, it seems logical to set up one big cloud-hosted Moodle with enough hardware capacity to cater the needs of the entire uni.
Also, consider this for a multitenant set up:
What happens when a student in department 1 (Moodle 1) wishes to take electives from department 2 (Moodle 2) and department 4 (Moodle 4)? He/she won't have a central dashboard outlining all of his/her course details, but 3 or more. He/she may have SSO access to all Moodles, but has to manage his/her dashboards from different URLs.
In the last few years, I've seen various successful Moodle implementations in academic / higher education with well over 15k users running smoothly.