I had a feeling this would not end well. It's probably why I bought some alcohol on my trip to Monoprix this afternoon. I have been beaten by internal cable routing, badly. I even tried the dental floss method, only to lose my cable AND my floss.
I don't have a way to change from one chainring to another now, but at least I've got something to drown my sorrows in. The cup will definitely be half full tonight.