FAT 32 is really not so bad. Consider having a small partition that is just FAT 32.

I dual boot. I have Windows on NTFS partition and Linux on ext2. I also have a chunk of fspace that is FAT-32 that both can write to so I can adjust for storage need changes easier.

Just install RTW to that FAT-32 partition and problem solved. A simple linux shell script would be sufficient for backing up and restoring the hibernation file.

Nice idea BTW.