Forcing low resolution and stretching to full screen

Hello,

I'm currently using an asset attached to my camera to pixelize my game by downsizing my resolution(at least in appearance). I'm wondering if this is a silly thing to do. Is there a way I can force a low resolution on the player and then stretch it to fullscreen to create the same effect? This way I'd get the visual I want but also a performance boost from being at a lower resolution. Or will this cause all kinds of unintended consequences?

Thanks.