I'm perfectly happy having FK Fic Fest run off DW alone in the future. Just make sure everything's safely imported before you delete! However, I do think there's a lot to be said for keeping the LJ in existence, with a sticky note. As it started on LJ, there could well be links that only go there; and you'll be pointing players-of-yesteryear to the new location.

Anyway, I've cross-posted for several years now. I basically just go over occasionally to check people/comms that are primarily or entirely LJ-based. As you point out, there are some. And not all their owners are deceased, either.

For the moment, I'm not deleting my LJ. It may be, of course, that people come up with very good reasons for wanting to remove all data from Russian servers; but frankly, I think it's too late for that. If they want it, they'll have scraped it already.