Xmas to/from Hawaii is all about timing ....
TO Hawaii Dec 22/23/24/25 = expensive, 26 either way, 27/28 can find good deals, 29/30/31 expensive again.
If your dates are very firm and you need to travel To Hawaii Dec 24 and back JAn 2 (for example), you will want to book sooner than later.
Flexibility in dates means wait for sure . . .