I have encountered this a few times and I thought of collating past experiences of other users on their successful attempt to restore the eco friendly hibernation feature. I personally favour hibernate than sleep as sleep slowly bleeds your battery away.
I just installed a 512GB M4 Crucial SSD into my laptop.
For my case, it happens when I tried to resize the C: partition to a smaller size using a third party software called minitool partition wizard. Windows native disk management somehow restricts the minimum size for C even though I have like 80GBs of free space. After successfully resizing it using partition wizard, i lost hibernation feature.
After searching the internet for solutions, many suggested powercfg cmd but this didnt work for me. I have also tried other recommendations and those didnt work too.
Since hibernation needs to store the OS states and apps into a file before shutting down, I suspected the pagefile.sys got corrupted due to the resizing and did a chkdsk with fix. It found some errors and fixed it. After a successful chkdsk fix, I got back hibernation feature!
I also recommend to leave the vritual memory to system managed as I read from other posts that hibernate needs about 4GB of pagefile to hibernate.
Hope this helps others who have similar problems. On the hand if you have successfully restore your hibernation feature, please post your experience here. Thanks!