Assuming this is a regular 12-game season, no post-season.
It would be better to throw out the high and low seasons first...as weird exception seasons always happen (injuries, hurricanes, forest fires that burn down opposing schools, etc.)
If you did that I would say the floor is 5 and the ceiling is 10, with 8 being the most frequent result.
Most years will be 7 - 9 wins, really good years 10 wins and the exceptional high years being 11 or 12.
Same on the bottom...if we end up playing our 3rd string freshman QB then 5 - 6 wins, but if that happens to also be the year that we lose our top five linemen to injury or have to play in another stadium due to a tornado, then 3 - 4.
Not a huge stretch, as this is probably true of all average P5 teams. I think to have 9 wins as the most frequent season you have to be perennial Top 25, and to have typical 10 win seasons you are perennial Top 10. This year there are five schools in the Top 25 with only 8 wins.