Harder, yes, but still good to note not impossible. There’s some cryogenic techniques that allow them to preserve what’s on the RAM long enough to read it.
It’s a bit of a long shot, and I’m not sure if it’s just theory or proven in reality. The idea is that you literally freeze the memory at a cold enough temperature to freeze the state of the memory, and then swap the memory into a machine with power in order to read or dump the data
It’s a variation of a cold boot attack. Instead of forcing an OS crash and rebooting into an OS connected to a portable drive, you cool the memory to extend the time you have before the data degrades and can then do whatever you want with it. I believe you can extend it up to a week.