Soldier Field could be designed to handle upwards of 125,000 fans, easy. Heck it had 115,000 attend a high school football game there in the '30s (no I didn't watch it.....I'm not quite THAT old).
For those who want a fancy roof top and all the comforts of home, I have no problem with those folks - but stay home then - and watch football on your TV. You'll probably see more than you would as a spectator in the zillionth row of a 125,000 seat stadium anyway.
Part of the great Bears football experience is being out in the brutal elements. Real men battling on real turf - even if the field is like a lunar landscape at times or the frozen tundra. I realize folks like Jerry Jones thinks you need the Dallas Palace to enjoy watching football, that a little rain and snow & men battling it out in the mud and blood is "distasteful" and unrefined for people of today. But I think that's what "real" football is all about. As Ditka once said "it ain't tiddly-winks"...
America is turning in a bunch of fat soft people.