NE FB is the only show in the state. 
They do not fill the stadium with only folks that live in Lincoln.
The population of the Twin Cities is far greater than that of Madison.
If the Gophers were the only show in the Twin Cities they probably would draw better. NE draws very well despite a mediocre record over the last fifteen years.
The underlying mistake in logic is that the WI stadium is mostly filled with folks that live in Madison.
It is not. 
WI draws from all over the state as NE does.
		
		
	 
You're kidding about Nebraska, right? If the Gophers had their record, attendance would change dramatically. This is starting after the Huskers' THREE national championships in the 1990s. They even won eight games or more in two of the four "dreadful" Bill Callahan years. (Numbers at the end are Nebraska's finish in the final coaches poll and AP poll. I wish I knew how to format better on this site.) 
1998	9–4	T–2nd (North)	Holiday	20	19
1999	12–1	1st (North)	        Fiesta†	2	3
2000	10–2	T–1st (North)	Alamo	7	8
2001	11–2	T–1st (North)	Rose	        7	8
2002	7–7	4th (North)	        Independence		
2003	10–3	2nd (North)	        Alamo		
2004	5–6	3rd (North)	        --		
2005	8–4	T–2nd (North)	Alamo	24	24
2006	9–5	1st (North)	        Cotton		
2007	5–7	T–5th (North)	--		
2008	9–4	T–1st (North)	Gator		
2009	10–4	1st (North)	        Holiday	14	14
2010	10–4	T–1st (North)	Holiday	19	20
2011	9–4	3rd (Legends)	Cap One	24	24	
2012	10–4	1st (Legends)	Cap One	23	25	
2013	9–4	T–2nd (Legends)	Gator	        25		
2014	9–4	5–3	T–2nd (West)	Holiday	23	25	
2015	6–7	3–5	4th (West)	        Foster Farms