For lack of a better ranking system I will use collegefootballnews.com/2017/college-football-preseason-rankings-previwe-2017
BYU vs. arguably MWC team with best ability to get good non-conference games: Boise St.
Best: LSU (top 40) vs. Wash. St. (top 40)
2: Wisconsin (top 40) vs. CSU #56
3: Utah (top 40) vs. SDSU #57
4: Miss. St. #47 vs. BYU #58
5: Boise St. #54 vs. UVA #71
6: ECU #89 vs. Troy #79
7: UNLV #94 vs. Air Force #82
8: USU #98 vs. Wyoming #90
9: Fresno #103 vs. Nevada #91
10: Hawaii #104 vs. USU #98
11: SJSU #113 vs. Fresno #103
12: UMASS #126 vs. UNM #123
13: PRST (FCS) vs. None
Boise's best four opponents are all away games and two of them are MWC teams. I would also argue that difference in quality of opponent ranked between 80-130 is essentially meaningless. I would much rather have our top 5 games, than Boise's top 5 games. Our schedule would look worse than our current schedule, every year, if we were in the MWC (regardless of how many MWC games we have this year).