Went to a wedding in 2018 at the end of September when the Brewers were 1 game behind the Cubs for first place with 2 games left. Most of us were in the bar watching the game, instead of the reception hall, even the bride and groom popped in every so often.
My opinion, whether or not you're a sports fan, I think you have to take into account the sports atmosphere where you live/where your guests are from. I don't mind missing a game in the middle of the season, but I think if you're going to schedule something during an opener or potential postseason/playoffs of a sport, try to have it where there's a TV.
Can't imagine there's too many weddings around Ames/Iowa City opening weekend for football.