Trying to open a devcontainer in a remote workspace, when the `.code-workspace` file is local

So, I keep a folder of .code-workspace files for the projects I'm working on. Each of these dictates a remoteAuthority to a remote development server on which we do our work:

{
   "folders": [
      {
         "uri": "vscode-remote://ssh-remote+nspawn/home/me/code/dune"
      }
   ],
   "remoteAuthority": "ssh-remote+nspawn",
   "settings": {
      "ocaml.sandbox": {
         "kind": "opam",
         "switch": "${workspaceFolder:dune}"
      }
   }
}

When opening this specific example, since the Dune project has a devcontainer.json, I get this prompt:

Unfortunately, it complains about being unable to find the .code-workspace (I assume because it's looking on the remote, not where it's actually located, on my local machine):

Ideally, this would "just work" (auto-launching a detected devcontainer, when connected over Remote-SSH, and when the .code-workspace is local) — short of that, a workaround would be appreciated. 😅