All it will do is change the look and cost you more money to buy (4) 20” wheels and then have to buy 4 tires to fit. In addition, if you price the exact same tire (brand / model) in a 17” VS 20” (equivalent height and width) it will almost always cost more money for the 20” tire...Sometimes substantially more money even though they are the same overall height and width. If you are trying to do so because of appearance, you’re not limited to those 2 sizes. You can put an 18” for example. What are you trying to accomplish?
the 20's will have a shorter side wall & be a but more stable, less side to side sway.
here's a shot of my 2014 Q Cab on the factory 20's (33 in tires) & with 17's (33in tires)
And just for S&G the newest look on 20in steels with 30in tires