I have two (hopefully helpful) comments.
1. If you want to arrive early and don't mind standing in line in case they enforce check in time, go for it! Yes, it is annoying to deal with a crowded terminal, but I won't judge you!
2. Even though you missed the 45 day check in, additional check in spots DO open up. I have had luck with this multiple times. I have seen earlier times appear 1 week before departure. Just keep checking the app and you might get lucky.