As I found out today after three solid months of use lol. Power usage went from 30-35W to 20-23W while watching YT.
For anyone interested, I used the optimus-manager method. For this, I installed optimus-manager, put the following config in /etc/optimus-manager/optimus-manager.conf and gave it a reboot.
[nvidia]
modeset=yes
PAT=yes
allow_external_gpus=no
options=overclocking
dynamic_power_management=fine
You maybe ought to give the related Arch wiki a read through as there are some gotchas and you could possibly get stuck with a locking-at-boot system, needing some advanced jiggery-pokery.
edit: code blocks aren't working