Originally Posted by SchmutzigMSP

I doubt NW is "making it impossible". Keep in mind the partner airlines (KE, HA, CZ, etc.) also need to have seats available for partner award tickets. If they have no availability on those dates, it doesn't matter how badly you or NW want the seats, they just won't be available.

Keep looking at all routes and all combinations of routes and be as flexible on the dates as possible. Remember, for all possible sets of flights on any given day, the same set (usually) exists on the previous day and the next day. Ask the agents to check each combination on each day. Persistence can really pay off in situations like this.

Good luck.