There are no tricks, just persistence. I think 'Ohana is among the top 5 most difficult places to book. Check online multiple times a day starting now because people will cancel if their plans change since it has a credit card guarantee and a financial penalty that most will want to avoid. You can try calling, but online is faster and the phone CMs see the same availability as the online system. You don't say when in November you're going, but November reservations have been available since May so it's not surprising that 'Ohana is booked.
If you're flexible about your date that will help. Also, late evening reservations are more likely to open up as other people who are checking try to get earlier in the evening reservations and cancel their later ones when they're successful.
Although 'Ohana has tables for larger parties, you could try looking for reservations for smaller groups (e.g. 2 reservations for 4 each), but you may not be seated together. With a group of 8 it's possible you'll be seated at more than one table anyway.
You can continue checking even after you arrive at DW. As a very last resort you can try walking up, but with a party of 8 I don't know how likely it is that they will seat you. Most people suggest trying walk ups when the restaurant opens or near closing time.