re: Office 365 having a big outage at the moment

Yep, just looked into it:

"Starting at 09:29 UTC on 04 Sep 2018, customers in South Central US may experience difficulties connecting to resources hosted in this region. Engineers have isolated an issue with cooling in one part of the data center, which caused a localized spike in temperature, as the preliminary root-cause, which has now been mitigated. Automated data center procedures to ensure data and hardware integrity went into effect when temperatures hit a specified threshold and critical hardware entered a structured power down process. Engineers are now in the process of restoring power to affected devices as part of the ongoing mitigation process.

"Some services may also be experiencing intermittent authentication issues due to downstream Azure Active Directory impact, and engineers are separately working on mitigation options for this also.

"The next update will be provided at 15:00 UTC or as events warrant."