of the beholder.
It's called acclimatization!
A kid who lives and practices in South Florida humidity all season will have a much different opinion of perfect football weather from a kid who lives and practices off Lake Michigan. These are simplicities that exist in the real World that just shouldn't need to be explained.
The more complex side of your ridiculous take, is the "better team". Any given day, one team could beat another when you are talking about the upper (playoff) level. If team A beats team B twice in the regular season (home and away) but loses to them in the playoffs at a neutral site, who is the better team? Which one counts? In '88 could we have beat Miami in a best of 5 at a neutral site? Would we have won if that game was AT Miami instead of in South Bend? We beat Clemson in '20 but then got smashed in ACC Championship.
All that matters is who wins when it counts...that is who the better team is and if one team is more acclimated to the cold then that WILL give them an advantage playing in the cold while if another is more acclimated to heat or humidity it will give them an advantage playing in those conditions.