I think you undersell Washington a good bit. A few years ago Forbes had them ranked as the 19th most valuable program in college football. One behind USC and 6 ahead of Clemson. They would be a major addition to any conference.
And the fact B10 didn't have interest in them now when they could have them basically for free, when in another year or two there will be a new deal and new media rights, says alot about how big of brand you have to be to get an invite right now.
I still don't think the big 2 will ultimately add many more schools - 2-4 each at most, and it may occur in the next 3 years or it might occur over the next decade.
FSU is not in a particularly strong spot right now. They don't bring any major markets, they have a fanbase issue (they have one of the lower % of scanned to announced attendance among P5 schools at 57%) and their FB program is not strong right now. Clemson is clearly the stronger brand right now. If FSU doesn't start to improve quickly and get its fanbase back on board then it will have issues trying to move up.
If I was ranking programs right now for potential movement it would probably be
ND (eyeballs - 7th largest average viewership in college football, - both of the Big 2 would bend over backwards to add them to their conference, but ND has made it clear it isn't interested at this time, we'll see if that changes in a couple of years)
Clemson (eyeballs though smaller and more regionalized than ND)
Oregon (large state school, Nike money)
UNC (large state school, neither of the Big 2 have presence in the state that is one of the 10 largest and growing), Washington (large state school, big market), Miami (because they are showing they have alums who will spend money like crazy)
FSU (mostly based on past success, if the program doesn't get better than it falls back to the everybody else category)
everybody else.
SEC largely prizes Sunbelt schools with large fanbases over all else.
B10 is a little more complicated. They tend to favor large schools (preferably 'the school' in the state), preferably in a larger market and with a good academic research University that it can add to its consortium.
I don't think there are alot of attractive options for the Big 2.
ND is obvious.
In the PAC10 both Oregon and Washington have some value, but not enough to be automatic invites.
Stanford has value to the B10 if it could guarantee getting ND with them, but unless it was a guarantee than the value isn't there.
There are no schools left in the B12 that really move the needle imo.
In the ACC, Clemson is probably the most attractive but you can make a strong case that UNC might be more attractive overall (though UNC would never ever leave the ACC)
FSU and Miami have some value but below the 2 other ACC schools
GT could have a little value for the B10, but not if they have to deal with any legal and/or financial issues. GT has no value for SEC and doesn't fit what the SEC looks for at all.
I also find it funny that fans are like 'we should offer ourselves to the highest bidder'. You have to have bidders first. I'm sure both conferences have had schools reach out to them, but right now all they are doing is basically creating a waiting list and probably prioritizing and at some point in the future when it makes sense they may start moving on their waiting list. But just like college admissions, the majority of entities on that waiting list will never hear their name called.
