Even we have bigger squad Pep still have preference of player that can he can trust to play so either way he will play it like he have small squads. Pep sometimes not even trying to use substitution for a whole match is indication for that.
Two years before, Pep complain of lack more substitution to be used yet when PL implementing more substitution can be used in the match he doesn't take that option more often.
So either way even if Pep is given a bigger squad will Pep even use all of them, i don't think so.