1982 when Utah population was 1,558,314. Rough current Utah population is 3,417,734.
If BYU builds a bigger stadium people will come and fill it.
Also.. I don't recall many CBers complaining about when BYU played in either the Vegas or Dallas NFL stadiums.
Also fun fact..
"The stadium expansion increased the seating capacity to over 65,000. The crowd of 64,253 that gathered for BYU's first game in the expanded stadium on September 25, 1982 was reported at the time as "the largest gathering ever in Utah history."