The menu is Cabanas is a limited selection from that night's menus available in the other dining rooms, so you're not going to necessarily get more options there.
Generally, the first time you dine in each dining room you get that room's Signature Menu (different menus in each dining room). If your cruise is longer than 3 nights, the subsequent nights the same menu is served in all dining rooms. These other menus are Pirate menu (for Pirate night); Captain's Gala (usually semi-formal night); Prince & Princess menu (formal night); Til We Meet Again/See Ya Real Soon (last night).
Longer cruises will have other menus. Every night you'll get a different menu on a
DCL cruise.