Hiyo,

Just a little suggestion, schedule the servers maintenance to rotate, so there's at least one server up at a time, examples:
Option 1; Rotation with Hardcore server - reg servers down except for Hardcore server starting at 9 EST to 12 EST, 12 EST reg servers up and Hardcore down till 15 EST.
Option 2; Daily - Sunday Argonnessen maintenance, Monday Cannith maintenance, Teusday Khyber maintenance, etc..
Option 3; Hourly - 9 EST Agronnessen, 12 EST Cannith, 15 EST Khyber, etc..

Cheers