@cornfeedhobo - I hope that you’re able to figure out what’s causing it not to work. After I finally got it working on Pop!_OS it has been fantastic.
In case it may be of some help, here are the relevant lines in my sleep.conf and logind.conf files:
etc/systemd/sleep.conf:
[Sleep]
#AllowSuspendThenHibernate=yes
HibernateDelaySec=120min
/etc/systemd/logind.conf:
[Login]
HandleLidSwitch=suspend-then-hibernate
HandleLidSwitchExternalPower=suspend-then-hibernate
IdleAction=suspend-then-hibernate
IdleActionSec=30min