SCCM Update management for roaming clients

Hi together,

I am currently running WSUS as MS updates management solution, but with lot of home-office and roaming clients not connecting to the corporate network, this becomes an issue.
I want to keep selected products and classifications, different WSUS target groups for different update waves and tiers, and automatic approvals for the latter based on classification criteria and sites.
I also want to keep computers download the approved updates from Microsoft directly, as configured in WSUS under Update Files / Do not store update files locally; Computers install from Microsoft Update.
While piloting modern management design through Endpoint Manager (SCCM) with an internet facing Cloud Management Gateway (CMG) for roaming clients, I cannot identify a documentation on how to achieve the above - all WSUS migration guides are requiring local updates repositories, which is counterproductive for our computers which are not regularly VPN connected, but are constantly online and can speak to the CMG.