There is no min or max vis value for any aircfaft type or any pilot type. Vis is not actually measured along any taxiway anyway, the vis quoted in low vis procs is three defined points along the lenght of the runway, the touchdown zone, the runway mid point and the end of the runway. these values are constantly varying due to the nature of fog they are almost certainly not that representative of conditions else where on the airfield.
If you taxi slowly enough, using airfield charts and your magnetic compass you should almost always be able to folow taxiway lighting to a runway which will then have much brighter lighting. The danger is not seeing a less well lit object. If in doubt......stop and tell ATC.
Did hear a story of a 747 that autolanded in thick fog, and came to a stop on the runway ( the aircraft will track and stop on the centreline if full 3B) but the upperdeck was above the fog!! 10k vis from the flight deck, but still couldnt taxi!!
