Out of curiosity, does anyone's opinion change if we end up just taking a couple of Liga MX teams, a la having a couple of the top Canadian markets? Let's say Club America, Monterrey, Chivas, and Tigres for illustration. Throw in expansions in Phoenix and Detroit to make it 36:
Eastern Conference
Atlantic // Toronto, Montreal, New England, New York City, NY Red Bulls, Philadelphia, DC United, Orlando, Miami
Central // Minnesota, St. Louis, Chicago, Detroit, Columbus, Cincinnati, Nashville, Atlanta, Carolina
Western Conference
Pacific // Vancouver, Seattle, Portland, Sacramento, San Jose, Los Angeles, LA Galaxy, Chivas, Club America
Mountain // Salt Lake City, Colorado, Phoenix, Kansas City, Dallas, Austin, Houston, Monterrey, Tigres
Play your division twice (16 games), the other division in your conference once (9 games), and play one of the two divisions in the opposite conference once (9 games) on a rotating basis for a total of 34 games. That would be three road trips to Mexico each year if you're in the Western Conference and one each year if you're in the Eastern Conference.