Yeah so rabid the team moved to another city because no one showed up
Looking at the numbers and my spotty memory, the Expos attendance was not good, about 24K average per game, through 1995, which is not horrid as seen by the Rays and Marlins over the last few years - 15K and 10K average per game respectively of which a huge chunk for the Rays can be credited to Yank and Red Sox fans attending games there.
The Expos had some good teams with guys like Pedro and Raines; but, players were always challenged by Canadian taxes, the exchange rate, and the venue. Olympic Stadium was built in 1976 for the Olympics and was not intended to be converted to a baseball stadium unlike the Brave's Turner Field. By the late 1990's, it was a mess. The team's financials, which were already unstable to begin with, were crushed by the 1995 player's strike, which subsequently lead to payroll purges and ownership changes. By the time the 'San Juan Experiment' was underway less than a decade later, the team was drawing 10K per game, which was considered a calamity by MLB; but, oddly, they don't seem to be as concerned about the Marlins while Tampa is indeed in limbo. MLB, which owned the Expos by that time, had publically declared that the only way to 'save the team, i.e. sell it for a profit, was to move it to DC and sell it (Lerner). The 'talk' of contracting the team was a PR ploy aimed at getting the player's union approval and, more importantly, to keep Baltimore (Angelos) from blocking the move.
As a FYI, MLB 'bought' the Expos from Loria who previously took control of the team from Brochu. Loria expanded the team's payroll from the post-strike level and negotiated a better broadcasting deal, which allowed him to 'sell' the Expos to MLB for a profit and then used that profit to buy the Marlins. The Marlins where for sale because its owner, Henry, wanted to buy the Red Sox. So, in summary, nearly everything wrong with MLB can be ted back to the Red Sox, LOL.
Montreal has is the 19th largest metro area in North America ahead of Seattle, MSP, Denver, and all of the rumored MLB expansion candidates - Orlando, Charlotte, Nashville, Las Vegas, and Portland, and is the largest metro area in the US and Canada that does not have a MLB team. It's also home to some major corporations, which is key for sponsorship and suite sales, such as: Air Canada, Bank of Montreal, Bausch Health Bell Canada, Bombardier, CNR, Molson Coors,etc. The city also strong supports its NHL team (of coruse) and MLS has done well in the city (abouty 18K to 16K aberage per game in a 20K stadium). Thus, with the right ownership, the right stadium (30K to 34K with a retracatble roof) and a commitent to be compettive, I think a MLB team would do well in Montreal.