Christmas in Hawaii

HI IMs
Looking to take the family to Hawaii over Christmas. Girls ages are 5, 7 and 13 plus my Husband and myself.
The 2 weeks over the Christmas and New Year is the only time my husband has off all year so travel other times of the year is impossible.
As its so close alot of the top resorts are booked out however I would like to stay in more of a resort style hotel close to the beach rather than a hotel without the resort features.
Most places I have looked at have kitchens which is great however I like the option of having buffet breakfast daily and pools with bars to relax in.
Looking for recommendations on good places to stay, pros/cons. Waikiki, Maui, Big Island or other destinations?
Was it ok to stay in a Hotel rather than a resort or is the extra money for a resort worth it? (Resort fees plus taxes etc)
How to go booking interconnecting rooms if family rooms are not available?
Any other tips would be great, things to see and do with children that time of year, where would you have Christmas lunch?
Tia x