When was the last time that happened to a Gmail account? It has unlimited cookie sessions.

Then connect the browser directly to the secure element of the device, so the session cookie is cryptographically signed by something you are physically in possession of.

Logging and alerting the user that their account is being used from a new context and requiring reauthentication when accessing the account from an unfamiliar IP/user agent would mitigate this to some extent.

TPMs / secure enclaves can (in theory) prevent sessions or cookies from being stolen. Not claiming there aren't other attack vectors though.

The alternative is offering offline versions of apps to students and allow students to open downloaded items off the cloud locally. It also means students don't require internet access when off campus.

I'll take that risk, especially since I've basically never heard of a successful attack hinging on a stolen session cookie being used for months. Either you do what you'll do within a few minutes, or you never do.