On Debian, you need to have secure boot disabled in order to hibernate. I’m guessing it works similarly on mint

Gather a lot of mint, put it in your cave in a pile, and lay down on it before going to sleep for the winter.

Haven’t used Mint in a while, but I think it’s mostly a function of the kernel. IIRC, there’s a nice GUI for selecting what kernel you want on Mint. Would probably only make a difference if you have new hardware and need a newer kernel.