Niagara falls in Canada already declared a state of emergency and Kingston is expecting to see 3x the normal population visit during the eclipse. It's going to be absolutely nuts and I feel for anyone living in a city like that.
My experience wasn't quite that bad, but still sucked. It took about 4.5 hours to get to my perfect spot. I left within an hour or two after the eclipse was over, and then it something like 8+ hours to get home due to excessive traffic.
It wouldn't have changed my choice, but I would have appreciated a warning that post-eclipse traffic could/would be extreme because it wasn't something I had even thought about. Figured it might be a little heavier, but wasn't expecting that much.
So this time around, I've mentioned it to folks who are planning to travel to see it.