I don't believe BYU will be more than a 10-14 point underdog at any point this year (and BYU actually did pretty well in those games last year).
I also believe that there are 9-10 teams that could beat BYU as well (and BYU didn't do very well as a small favorite last year - USU, NIU, Cal, etc).
I think a realistic expectation for a good season is 7-5 (1-3 vs P5 teams, 3-2 vs G5 teams, 3-0 in other games) but I'm hoping for better.