Depending on the age of the passengers (not too young or old) - be prepared to split up.

By way of example - my 4 Pax to Hawaii last week on the 26th out and 31st back looked like the following:

1-EWR-PHX-HNL in F (US)
3-JFK-PHX-HNL in F (US)
4 - Coach award HNL-ITO (HA)

return:
2- KOA-SFO-JFK in F (UA) (Lifemiles)
2- KOA-LAX-JFK in F (AA)

All of this was at the saver award level. Flexibility is the name of the game - along with miles in a number of accounts to take advantage of what is on offer. As other have advised - book what you can now.

One last suggestion...look at business class fares from HNL to BDA and other islands. They are remarkable in terms of cost(~$800-900 OW)- and allow free stopovers in a number of hubs enroute (not sure about Dallas).