INTERIOR AMMM by architecture, via Behance - Narrow vanity alongside the tub. This is what we have only our sink is centered (way too close to the toilet). I was having trouble finding images of off center sinks in this configuration.
Pinned for the idea. Not sure how much I like the extension over the toilet. If were to do, vanity top should be one piece, with no cut line. Also: Consider how much the extra counter space would be needed.