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Looking at the map, UNC and Virginia are somewhat logical. It's like the only part of the CSA that the SEC hasn't infiltrated yet, it's Big Ten adjacent through Maryland, and it is somewhat fertile recruiting grounds. I don't love it, but it isn't the worst idea that anyone has put forth so far. 

UNC and UVA would make a lot of sense for the B1G. 
If the conference doesn't get some kind of foot in the high-growth states, it's going to become the Ivy League in 50 years (if football still exists).  The VA Beach/Norfolk/Newport News area is probably a top-10 region for recruiting.  Charlotte is great, too. 
They expand the footprint.
The footprint remains contiguous.
Good population/high growth states.
AAU.
Good academics overall.
Plus good basketball as a bonus.
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If I was the commissioner of the B1G (don't go running off a cliff, this is just a hypothetical), I'd poke and prod those 2 schools to see what they're thinking and/or see if it's even feasible for them to leave the ACC.  It would've been my first call(s) when UT/OU to the SEC came out. 
Not some PAC-6 or Iowa State/KU silliness.

Yeah, the northern half of that map hasn't changed in the past 20 years.
CA, TX, and FL are already the top recruiting states.  GA, NC, VA, and LA are or have already bypassed every northern state besides maybe OH.  And the gap grows every day.  
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Top 5 Cities in terms of actual growth of number of people the past 10 years:
+234K Phoenix
+225K Houston
+221K San Antonio
+186K LA
+177K Austin..........NYC is 7th, and the only B1G city is Columbus at 13th.
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Top 5 Cities in terms of actual loss of number of people the past 10 years:
-43K Detroit
-27K Baltimore
-19K St. Louis
-16K Cleveland
-15K Toledo...........there are southern cities on the list, but 1/3 as many as northern cities.
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The population argument is akin to northerners on the Titanic assuring everyone that it's fine, everything's fine.  
You simply just need to look at the list of national champions the past 30 years to see it's not about strict population - it's about weather, youth, growth, and culture.  
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Bama Bama Bama?  Go back pre-Bama.  Florida, LSU, Florida, Texas, USC, LSU, OSU, Miami, OU, FSU, Tennessee!, Neb/UM, Florida, Neb, Neb, FSU, Bama, Miami/UW, GT/CU, Miami, ND......I consider that '88 NC by ND as a place-marker.  
What's the tally?  
Rust Belt:  6
Sun Belt:  16
Other:  2 (UW, CU)
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Since then?
Rust Belt:  1
Sun Belt:  11
Other:    0
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Going back to '88?
Rust Belt:  7
Sun Belt:  27
Other:      2
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AND THE GAP IS GROWING.

I'd take them

heck a deal could be made that details what happens years from now when the ACC GOR is closer to expiring

Metro area growth is probably more of consequence than inside the city.

I think any conference would take UNC/UVA, there is no real barrier there.  When you get to Wake and Dook it gets dicey.

VT, NCSU, fairly decent football schools.  FSU/Miami make an interesting pair but probably more for the SEC.

The city of Atlanta was losing population rather quickly for a couple decades while the metro area was expanding significantly.

I may be wrong, but I believe that The Big Ten Academic Alliance provides more money to the Universities than the TV Money provides.  I can't see the B1G bringing any school in that might dilute the academics since all schools of the B1G share in the BTAA.