Remote Sonos <> ST interation?

Has anyone been able to or know of a way that I can add my Sonos Speakers to ST without them being on the same network as the ST Hub (v2) please?

Spotify can access your Sonos speakers remotely so there is defo a way though but was wondering if anyone was able to do so with ST.

The reason for asking is that I have all my HA ‘things’ (ST, Ring, Arlo, Bink, Nest, Hue etc.) on a 4G Router and I do not want to expose this network to my home networks at all, want to keep it completely separate and isolated. With that said, my Sonos are obviously best placed on my home network(s) and easily accessible to all in the house etc.

I understand that ‘allegedly’ Sonos may have something in the pipeline however it may only work with their own app as it currently does with Sonos so it may not (it very well may of course) help the situation if and when they do release the functionality.

I am open to any suggestions you may have.