Ghosting is a real part of roleplaying, and if there is no communication that says "hey, I don't like this RP anymore" I prefer to see it as an indefinite paused RP rather than a dead one. If someone doesn't like the RP anymore it would be nice to get a head's up, but I understand that usually doesn't happen for reasons. 

I had a good RP going where my partner posted once a month. The posts were worth the wait, and in the meantime, I did some other RP's or wrote fiction for myself. She stopped visiting the website we RPed on years ago, but if she were to come back today and asked to continue where we were, I'd happily do that.

I myself am a "once a week" kind of RPer (although I have been slower, but I try not to be) and I make sure my partner is aware of this before we start, to avoid disappointment. 

The way I cope with setting up plots that get ghosted: I write them as fiction for myself.