Jace, Cunning Castaway +1 Ability
Yes, that combo would work to win you the game.

Jace, Cunning Castaway's -5 ability and Doubling Season would allow you to create an arbitrary number of Jace copies. Those Jaces that didn't use an ability yet this turn can activate their +1 ability, and all of them would trigger on your combat damage. With Laboratory Maniac under your control and more Jace +1 triggers than cards in your library, you would win as soon as the (n+1)-th trigger has resolved.