Taking into account the usual design considerations for ADFS (I.e. 2 adfs + 2 adfs proxy) servers, we have multiple companies on one domain (in separate OUs)
With AADirSync, we have a separate AADirSync server per company (i.e. contoso.com) syncing the users of that company up to their Office 365 main account. Can I federate my single ADFS deployment with multiple Office 365 tenants as the provider so they can take advantage of single sign on?