I got lucky. I am not subscribed to this community, and I am the only person on my instance. But what if I was subscribed and hadn't seen this post? This is too much responsibility for me.
I just shut down my instance until we can disable cached images. If that never happens, then I'm not bringing it back up.
Shout-out to https://github.com/wescode/lemmy_migrate. I moved my subscriptions over in a minute or two, and now, other than not having my post history, it's exactly the same.