Question:
If the hibernation file under OS/2 can only reside on a FAT16 partition, and the space requirement is RAM+X, then if one has +2GB of RAM, the whole issue is already mute, isn't it?
I mean the physical limit for FAT16 is 2GB flat, period!
 
Since the FS always has some small overhead of its own and the hibernation tool also wants some extra MB, there is just no way you could squeeze 2GB down to a FAT16 partition. And forget all else beyond 2GB RAM outright.