No, you can't leave it unattended otherwise the car sleeps. However, it will pick up from where it left off so you don't have to do it all in one hit. It's much faster from the USB as opposed to DVDs.
Whether it will give you seven-digit postcode if you didn't have it before I don't know. My understanding was that the operating software and the maps would need to be upgraded.
Current: 2014 F31 320d M-Sport, Professional Media, Visibility Pack, Reversing Camera, DAB
Previous: 2013 F10 520d M-Sport, 2011 F10 520d M-Sport, 2008 320i M-Sport Coupe, 2002 325i, 2001 318i valvetronic, 1998 318i, 1996 525i, 1990 Porsche 944S2