>>57197807hm.. thinking of it like this, it'd probably have to be one of the games before the mandatory EXP share happens, because when that's on, the EXP gets halved a few times (say you'd get 2000 with 1, you'd get about 350-ish between 6)
it'd also need to be a game where exp gain is easy, and trainers use a lot of pokemon. I would say black & white (1 or 2 either-or), but that's purely because they kinda upped the ante for the trainers in that game, the exp dropoff could cause some issues.
it probably wouldn't be gen 7 at all either, because sure, while there's a lot of trainers, the totem battles don't have the trainer exp multiplier.
..of course, this all depends on if you actually manage to beat the trainers with relative ease on your first go.