Turn back the clock at ANGC, cut down the trees they planted and rough they grew, move the tees up to around 7000 yards give or take -- all predicated on also requiring the older Masters ball during the tournament.
Medinah #3: rebuild many of the greens and maybe green complexes, to make them more challenging for the PGA pro game.
Pebble: turn Doak or C&C loose on the ordinary holes, and see if they can make them better. Tom, if you see this and it's politic to answer, do you think you could improve any of those holes? In this thought experiment, you are given free reign over routing, hazards, greens, moving earth, the whole nine yards.