For getting same level of comfort for the same car, if you increase tyre size, then air pressure in tyres be decreased, otherwise, ride will become very bumpy and uncomfortable
This is my opinion based on my personal experience with my Vitz. 32-35 psi in stock 165/70/R14 tyres as per OEM requirements was absolutely OK, but the similar pressure in new 185/65/R15 tyres with 15" rims, made the ride extremely bumpy, uncomfortable (so had to drop tyre pressure to attain same level of comfort, otherwsie, suspension would have taken a Great Toll!)
Similarly, 32/30 psi in 175/65/R15 in Honda City Vs 32/30 psi 195/65/R15 for the same Honda City, will make lots of difference.