Good to know! :) I'm still trying to figure out how to get the instapaper-option to work with lj/dw (I'm having trouble staying logged in recently, so I tend to get an entire ebook's worth of "you must be logged in ..." or "please confirm that you are over 14/18/whatever years of age" messages), but other than that, I'm very, very happy with it and super grateful to you for sharing this workaround.

Btw, in case anyone else has trouble with instapaper-created epub files (for me, entire chapters would show up as "there", but were empty / had only one accessible page): converting them to .mobi and back did the trick.