With a month to go, this is how I think it will play out on current predictions and trends.
Keep an eye on Georgia, especially. Not a critical state (that's Penn, Wisc, etc, the "rust belt"), but rather a litmus on how much Trump will lose by.
I remember in the 2008 election contacting a US Dem pollster and suggesting that was winnable in the longer term. They didn't think it was quite ready, yet.
If I were the Dems, I'd be looking hungrily at Texas in the future as well.