The issue with your logic is the Rose Bowl can pick whomever they please (assuming big ten champ to the playoff) regardless of CFP ranking. PSU being a spot or two ahead of Minnesota doesn't necessarily mean anything.
That said if you want as much separation as possible between PSU and Minnesota, the path to it is likely Minnesota losing to Wisconsin handily and Michigan keeping things relatively close with the buckeyes, and finally Wisconsin keeping things closeish in the ccg. Then your final big ten rankings end up being OSU, PSU, Michigan, Wisconsin (Or Wisconsin, Michigan), Minnesota. I have a hard time believing the rose bowl is going to pick the fifth highest ranked big ten team over the second highest.
This whole "the Rose Bowl can pick whomever they please" stuff that is repeated is not exactly based in precedent. In theory, yes, the Rose Bowl is going to place some influence onto the CFP on a matchup when one or both conference champions are in the playoffs. However, there is zero history for the Rose Bowl not having the highest ranked team in the game since the playoff era.
In the CFP era, we only have 5 Rose Bowls to judge what they would do with their pick.
- 2014 - playoff site so can't consider
- 2015 - MSU was B10 champ went to playoff, Iowa was #5 and OSU was #7. Iowa went. Stanford went as Pac12 champ.
- 2016 - PSU was B10 champ went to Rose since they didn't get to the playoff. UWash did go to the playoff and was replaced with the next highest team -- USC. Should note that USC finished 9-3 and Colorado finished 10-3 with a loss in the Pac12 champ game. USC did beat Colorado earlier in the season.
- 2017 - playoff site so can't consider
- 2018 - OSU was B10 champ went to Rose since they didn't get to the playoff. UWash went as Pac12 champ.