There are a number of approaches you could take for this, and maybe some existing render farm solutions that I’m not familiar with. You’d likely want to unpause a server or develop a solution with containers.
One thing to be aware of with your experiments is that every installation of Unreal Engine also comes with UnrealEditor-Cmd.exe, which is the headless version of the engine. You can create a python script to load a level, import a USD file, and render. Assuming you have such a script, here’s a Powershell script to launch the editor and run that.
RunEditor.ps1
#Setup variables
$engine = "C:\Program Files\Epic Games\UE_5.X\Engine\Binaries\Win64\UnrealEditor-Cmd.exe"
$project = "C:\MyFolder\MyProject.uproject"
$script = "C:\MyFolder\MyScript.py"
#Start headless editor with specified script. Backtick ` used to preserve quotes in argument list.
Start-Process $engine -ArgumentList "`"$project`" -run=pythonscript -script=`"$script`""