Here's one with the door at the thin end at 4ft x 8ft (122 x 244cm). A door opening outwards helps things along, as do shallow sinks. Another tip is to nestle the sink and toilet cistern into niches in the wall which means them stick out less into the room. The minimum width you can get away with is about 4ft (122cm).
Virtu USA MS-2036-WMSQ-WH Caroline 36-Inch Bathroom Vanity with Double Square Sinks in White and Italian Carrera White Marble Virtu USA http://www.amazon.com/dp/B00CL3VAWQ/ref=cm_sw_r_pi_dp_3VcSub09NDBT9