The total seating has been lowered with the new visitor's tunnel, the bands being in the stands, and new wider spacing of the seats.
I agree that the home noise is a bit of a factor beyond out control due both to size of the school, our location nowhere near a metropolitan area and the average age of the attendees which, to take a random guess, is probably double that of what was at Georgia.
I remember a game where I sat next to a group of 8 of what look to be nuns easily in their 70s. While they paid rapt attention to the game, they never clapped, never stood up and barely spook a word. I am rarely at a game where I don't see the same type of older attendees who seem to be more bothered by fans who stand up than to who's winning the game. Nothing we can do about that but, in the absence of a large student body, the noise levels are rarely going to get like it was a Saturday night.
And if folks what complain about a "sea of red" type games, you have to look no further than the employees of ND who sell their tickets in droves as well as the fact that ND stadium is a "bucket list" place and game for most every opponent we play which typically means the a "big" game allotment of visitors seats are going to soaked up quickly by those fans.