Personally, I'd just do the wiki-wiki (interisland). What fare bucket is the current return booked in and is there still availability? You not only could have a change fee, but an up-fare to boot, depending on the competence of the CSR.

Given the short hop from OGG to KOA, it's possible you might get on-board at KOA prior to the itin zeroing, but might get stuck in ORD. Personally, I wouldn't chance it. Given time of year and route, such might leave you with few options.

What I would do is book the wiki-wiki, now.

Of course, you could always gamble on a "schedule change" ..... but doubtful at this late date and for that routing.

Pat