Can I override screen.width and height to help me scale poorly coded scenes to other screen sizes?

Hi, I'm starting to look at options to approach a bit of a bandaid fix that is avoiding a much bigger coding project. I have an application I'm working on that has maybe 35 scenes. They've been created by several different people (mostly not me), and were created for a specific screen size, resolution, and aspect ratio. What I'm hoping to do is to be able to make the scenes think that they're in a certain resolution even if they aren't, then I could maybe use another camera or something to scale/letterbox/translate to other screen sizes and resolutions. Lots of code was written poorly here to tie this project to a specific scenario, and it would be a much bigger project to go and fix all the code (and much of it isn't just code, but unity editor scene work as well). Any ideas or suggestions would be very very much appreciated! Thanks! Randy