Its an interesting question.
For the correct answer you have to look beyond the players and at the coaches.
Mike O'Shea's form chart says he's an ultra-stubborn good 'ol boy coach who will stick to his starter well past his best before date. Just look at how long he stuck with Willy the Pooh!
O'Shea also knows (in his heart of hearts) that Willy is unfit for service and only hanging around until Kyle Walters can secure a better (and more affordable option).
If Nichols can't handle the rambunctious Sasky crowds (think of a chain gang where each member can bellow louder than Pavarotti) he'll quietly succumb to an inferior Sask'n team but a superior CFL QB (Durant).
Campbell isn't as tied to his choices as O'Shea. So if Harris can't get 'er done - he'll roll out Hank.
I also think if Nichols trips over his boot-laces O'Shea will insert Willy for cleanup duty once the game is out of hand. Willy might even rack up a few points in garbage time - cuz that's his specialty!
But knowing O'Shea when the media tries to torment him to give up his starter in the Banjo Bowl - he'll stick with Nichols.
If Bombers get trounced home & home vs. Sask'n - then Houston we got a problem!