You don't necessarily need a special hidden partition for hibernation. It depends on the laptop design. Some BIOS require a save-to-disk partition, others use an immovable, contiguous file on the disk's normal file system. Some BIOS can be set up to use one or the other.
A catch though: You must have sufficient reserved space in the partition/file to cover both RAM & video memory + a small amount for overhead. If you increase the memory then you must repartition/re-establish the save-to-disk partition/file to have hibernation available again.