Yeargh... Maybe this'll work? (I tested it, it seemed to.)
Open the DVD with VLC, go to the title you want to transcode, then stop playback. Use the Transcode wizard, choose "existing playlist item" and select DVD from the list. Click Next, then select both transcode video and transcode audio. Select the dummy video codec (at any bitrate) and either the MPEG audio codec or MP3 audio codec. Click next and choose the MPEG 1 container format. Choose the path to save, and you'll probably want to deselect the local playback option.
You could also extract the VIDEO_TS folder, and transcode the .vob files one at a time.
I think this only transcodes each title section one at a time, so you might need to do it several times to get the entire Disc.