@hieroglyph With an established s2s vpn you could connect remotely to the server side of the vpn and access both sites with one connection, concurrently.

But this adds unecessary points of failure. And since these are home networks, you could be better off with two openvn servers listening at each site , and connect to each as needed.
A site to site vpn could also co exist, so you don't have to do anything when at home.

of course you can have it all. S2s, two openvpn listening at both sites, and access to everywhere no matter where you connect.

Happy tweaking.