Agree with this. Detroit, Boston and the Chicagos should open on the road.
There are 15 stadiums that are either in warmer areas or have a roof: Seattle, Oakland, SF, Dodgers, Angels, Padres, Arizona, Texas, Houston, Tampa, Miami, Atlanta, Milwaukee, Toronto, and either Washington, Baltimore, Cincinnati, St. Louis, or KC. Conveniently, those 15 teams are split evenly between AL and NL teams.
I think the home opener (as opposed to opening day) would sell out for several of the northern teams (Boston, NY Yankees and Mets, Philly, Chicago Cubs and White Sox, St. Louis). Likewise, when the remaining northern teams are competitive, almost all have shown the ability to sell out regularly. So, the issue seems to be whether the current scheduling is worth it in order to boost ticket sales for a single game in a few northern cities with non-competitive teams?