Keep in mind that the reason for the "free" zone is that, due to no fault of the person attempting to redeem the points, there is no valid routing completely within two zones. There's no secret to this.
I was recently checking on possibly iteneraries for a trip from Atlanta (the divider between two zones) and Seatle. At the time, the only valid routing was through Washington, DC. This would still only be a two-zone award, despite crossing the entire country, due to the routing rules.