you can't do that.
you might be able to sort something out with a VPN, but homekit requires network broadcasts, which can be problematic on VPNs. and more than likely would be more trouble that it's worth, Plus homekit is not really set up to have different homes on the same hub, so you would wind up with everything in the same home.
it doesn't
There are 2 locations
--at home with hubs
--at work with no hubs (there is "at least one aTV", but doesn't sound like they belong to the poster, so aren't logged into his appleID, so for this case, they're basically non-existent)
homekit can handle multiple homes on the same appleID, but each home must have a hub located there.
you've made it more complicated than it needs to be by having multiple appleIDs involved.
youve got me all wrong. we've moved on; him needing a hub at each location is established. in fact i am the one who recommended it.
in my last comments, i was postulating about the two hubs (in different locations), one icloud scenario, and i still think it would work. Each ATV in both locations would be the hub for its own home and can only see and work with the devices added to that home and visible on its respective LAN.
and what im doing with -my- shared homes isnt wrong or complicated. they all have separate icloud accounts because the devices (and homes) belong to another individuals and their icloud accounts. Via the sharing function you can have full access to multiple homes and not be 'more complicated than it needs to be'.
I was simply stating that im familiar with using a multi-home setup, but not with two hubs at two different locations on my single account. That said, I think it would work as i described in my previous post.
ALL that said, he could just setup the plugs on the office's ATV existing icloud account and then within Home, share the office 'home' with his personal icloud and be done.
he doesnt have to buy anything else, doesnt need to share his home, and doesnt need longterm access to the icloud account of the work ATV, only to setup and share the home.
if one works in a small, friendly office, others could do the same thing and share the OfficeKit! Prepare for pranks