I'm in the middle of upgrading a small business domain and my favoured option is switching to Azure AD and removing the on-premise DC. However, I'm concerned that if connectivity drops (ISP maintenance/outage) that:
- Existing login sessions could be terminated
- Login will not be possible for the duration of the outage, plus the time it takes workstations to reconnect to the cloud DC
All workstations have local admin accounts of course, but this is a secondary option. I can't find documentation for what is possible when the DC is not reachable, or if successful credentials are cached on workstations (since it copies profile info from the DC on login).