Correct way to handle buffers opened with TRAMP? Particularly when the buffers and underlying host are no longer available.

I saved a couple of Activities representing coding work on remote systems with buffers opened over TRAMP. The underlying host (and its buffers) are no longer available. Now, even with a TRAMP buffer and session cleanup via TRAMP's interactive util functions, activities-resume and a couple of other activities functions hang indefinitely and require a C-g to get Emacs back under control.

Curious if you have any advice on how this should be handled? It doesn't necessarily seem like a problem with the activities library so much as the usual silliness from TRAMP. But perhaps there's something we could do to recover from the activities side?