Aside from a Winter Classic - and given the success of the Stadium Series - I'm sure the plan would be to play more than 1. It would likely be 2-3 per year. Given the appetite for hockey in the area, MLSE could pull it off.
I guarantee they'd make more money off one outdoor game than a season of CFL games and maybe even a season of MLS games.
The outdoor games are huge money makings. And you have to think outside of just the game itself. The merchandise alone too makes a fortune.