Perhaps the BEST B1G Forum anywhere, here at College Football Fan Site, CFB51!!!

hah, think more like $160/month, 12 months a year
at $1/month to all the little old ladies in the states of New Jersey and New York paying for basic cable with the BTN is much more than all the fanatics paying $100/month
When/if the FCC brings out ala carte programming - us crazy fanatics are going to pay DEARLY for our CFB content
probably just go to purchasing individual games, such as PPV.  Your option on delivery method, IPTV, CATV, streaming.  $50/game, maybe $100/game for the big matchups.

Some helmets are fading. Some are thriving. Some faded and came back to thriving.

I accept that "a helmet falling out" is theoretically possible and could take a loooong time. I also accept that the "they just took a prescribed time to fall out" theory can explain what happened to Minnesota/U-Chicago et al.
However, that theory does not explain why many helmets were lost in the 5 decades before 1970 but zero helmets have been lost in the 5 decades since 1970. That implies a phase change. So I think whatever our best model is, it must account for this phase change.

• The first reason is an obvious one but one that might be overlooked if not stated.  Over time starting from the beginning of cfb the "helmets" inherently tend to become more entrenched simply because they have more history of being "helmets".  If a team, lets say Yale, was the hands down indisputable best team in CFB for the first 10 years of the game (1869-1878) that could have been easily overcome by a team being the hands down indisputable best team for 15 years from 1879-1893 but each time this recurs it takes longer.  
• Television, and then the advent of cable and the lawsuit that ended the limitation of the televising of games:  If we think of a pre-TV era it was difficult, for example, for a Minnesota alum to keep up with Minnesota football unless they lived reasonably close to Minneapolis.  They could get a box score from the newspaper or perhaps listen to a game on the radio but they couldn't see a game without travelling back to Minneapolis.  Due to NCAA limitations on televised games this restriction lasted into the 1980's and even after the NCAA lost at SCOTUS (1984) it still took a little while for the change to take effect.  Today a Michigan fan can keep up with their team (due to the internet) and can probably watch all of their games regardless of where they live.  This allowed fanbases to nationalize more readily.  The teams that had the largest fanbases in 1984 were generally the same "helmets" from 1970 and all of them grew national fanbases that will take decades to fully erode.  

I don't think it will ever work like that.  The biggest games create more revenue when more people watch.  Ie, the advertising revenue for an audience of millions is more than the PPV revenue for a smaller audience.  I almost always watch the NC, but I wouldn't pay $100 to watch it unless Ohio State was in it.  
I think where they will get us for PPV is for smaller games that only us fanatics care about.  Ie, when Nebraska plays some MAC school they might be able to charge you money to watch it because they can't get a huge audience even if it is free.  

I was thinking of applying an attendance threshold as to what schools should remain as P5 representatives.

What would be a good number? Start at 50K and go from there? There are some P5 schools with stadiums that offer less capacity than that. 45K maybe?

Much of the SEC and B1G are safe in that zone. The ACC and PAC could be in trouble - particularly the former.