HERE is someone who went with 275/45/20 (slightly larger overall diameter, but could be done with a 40) on 4 - 20x10 replica rims.
 
The upside is all 4 corners can be rotated vs side to side.  Though doesn't look like he has the wheel lip arches.  Anyone know how much further in those 20x10 non-staggered rims would sit in vs the 20x10.5 staggered rims would?