Can hibernation be disabled when windows uses rclone copy
Sure - just turn it off as part of your script when you copy and back on when done.
yes, i have done that before,
powercfg.exe /change hibernate-timeout-ac 0 powercfg.exe /change hibernate-timeout-dc 0
also, might need to disable
powercfg.exe /change standby-timeout-ac 0 powercfg.exe /change standby-timeout-dc 0
or create a new power scheme, setup as you want and switch back and forth to/from that.
As people can come to this thread based on its title it is also possible in other OS.
In macOS run:
caffeinate -s rclone copy/sync/move...
Linux though is a real hard one to provide universal solution. It is very distro and GUI specific.