Connecting to existing network with 4G-stick

TL;DR: Can I configure my Opal to be a client in a existing network (with a existing router) where the Opal is accessible via a 4G-stick that’s connected to the Opal?

So my internet is failing often. But I still want to connect to my home network via WireGuard. I was wondering if I can connect a 4G-stick to my Opal at home and use this 4G-stick as a fallback for the WireGuard-Server on the Opal? So I can always connect.
But it’s important that I can reach all devices in the existing network including my main router. Connecting the 4G-stick to the main router is not an option.

Due to CGNAT this isn’t possible. While using 4G, you can’t use port forwarding, so no WG server will work.

You can try to get around this issue by using AstroRelay or ZeroTier - but the chances of success are not necessarily high.

Thanks for the reply. Already thought it wouldn’t be possible. Too bad.