Cat is out of the bag with going south, the ‘best’ schools in the south are massively popular with NE kids - Duke is the hottest school there is these days, with Vanderbilt, Emory and Wake Forest not far behind. And Davidson and Elon are getting there, plus UVA and UNC for people willing to look at state flagships, and Georgia Tech for STEM people. And a lot of more, getting out of the NE winters is a draw for a lot of kids, and some of the southern flagships offer good merit aid too (Alabama). I think if you want to get some real points for geographical diversity, mountain west or west north of CA (and the handful of CA SLACs) are probably your best bets.