OAK is typically cheaper to Maui than SMF. If you choose that as a backup, you should get a partial refund as well as transportation and whatever goodwill voucher they're giving you.

If you're willing to do it, take the money and get AS to book you SFO-OGG RT in F on VX for the same money and the goodwill voucher, then drive to/park at SFO. That's a much better product, which will ease a bit of the sting. If they can include UA flights SMF-SFO to get you there, even better.