Yes ETSU would be a great option if they were interested but they have a long way to go on their facilities if they even where interested. Their football program will be playing in a dome like Idaho only a smaller dome. Think it only hold around 12000.
They're not going to be playing in the mini-dome. I believe that was one of the requirements for starting football back up.
But even if they built the same stadium as Charlotte has, it appears that ETSU is very content being back in the SoCon.