Here's the thing about domes: They suck balls. They lack any personality, they feel hallow, and how the hell do you gain any home field advantage in a dome. The elements are what make War Memorial an intimidating place to play. You don't know if you're going to have a calm, sunny day, or if you're going to be in a 30mph blizzard, and believe me, that really screws with a SDSU player's head as they have no way to prepare for it.
The problem in Laramie is simple (concerning average attendance)... Laramie is in the worst possible place in Wyoming for most people to attend a game. It's hard to get folks from Sheridan, Powell, Cody, Billings, Jackson, Newcastle, etc to get to a game in Laramie when the roads start to get iffy. Yes, I know we're all Wyomingites and there's no weather we can't navigate, but there's also a very real possibility that past October 15th the road may close in Casper and you can't get any further South. And if you're over in Evanston, and sometimes even in Cheyenne (or Fort Fun/Denver area) you may not get to Laramie. That really cuts down on the number of people that are fringe season ticket holders. 10,000 really dedicated season ticket holder is cool, those people will be there no matter what happens, they'll come over a day early, leave a day late, but they'll never miss a game. It's the fickle fringe people that keep the stadium from being packed week in and week out. Wyoming fans have proven that the stadium will fill, we saw it against Texas, Boise, and now we'll see it vs. Nebraska. Part of it is winning, part of it is location, part of it is a sometimes fickle fan base. Lots of stuff in play here.
And with that, if and when the War is expanded, connecting the East and West side with a bowl on the South end would be cool! It would look a lot better than always bringing in temporary seating.