Detroit use to have some of the greatest hobby shows. One of the few cities with all 4 major sport teams. What about the Huntington Place convention Center. See all the details at their website.
Between the cities of Chicago and Cleveland. Across the river from Canada collectors, with Toronto only a few hours away.
Free high speed WI-Fi.
4200 parking spaces + 1000's more close by.
Greektown, many eating places etc.
Several Casinos in Detroit.
623,000 sq ft in contiguous floor space. Several other event rooms etc.
Etc.
https://www.huntingtonplacedetroit.com/
Just a thought and another option to consider.