HA has availability HNL-ICN in coach on 12/24 and 12/25, or business on 12/24. No low availability SEA-HNL after 12/10. Return at the end of January looks good for both legs on most days in coach. Business in much spottier.
I assume but don't know for sure that you can book an AA award SEA-HNL-ICN at AA's pricing. HA adds the prices for the two legs for awards in its own plan.