Hard to say. You will lose the Montreal portion of that record since their team is out.
But lots of casual fans tuned in and saw that game. I had numerous texts from non soccer coworkers asking me how the game was live. They may want to see how the book ends.
Maybe 800-900k?
Pretty impressive either way. Well deserved too.
Next season? I don't think you see a large bump, unless it's the Montreal rematch.