Working on Active Directory on a computer not joined to the domain

As long as you are connected to the local network, say with VPN or cable you can actually run the AD console as a domain user with:

%systemroot%\System32\runas.exe /netonly /user:domain\username "mmc dsa.msc /domain=domain.local"

For example:

%systemroot%\System32\runas.exe /netonly /user:abc.local\jsmith "mmc dsa.msc /domain=abc.local"

Note that you need admin rights to run the command. Also wile you are at it, why not make a shortcut with the command and make the shortcut run as admin?