It looks like you can, provided you have a server running somewhere. Mine is a 2013 MacBook Pro with a dying battery.
This one I'm writing in Drafts, which will then copy the post to a Dropbox folder monitored by Hazel. This should trigger a simple bash script that processes the markdown file and pushes the newly created html files to github.
Very Rube Goldberg-y, I know. I'll try doing it from Editorial next.