Will 225/55's fit on a 2016 with stock wheels. Bought the wrong size by accident and they're en route as I type this. i thought I chose 50s.

 

I'd say no. Stock size on an S is 215/45/17- those will be 2.5" taller!

https://tiresize.com/calculator/

 

The correct tire size for a 17 inch stock Mini wheel is 205/45-17. The stock 17 inch wheel is 7 inches wide with an ET of 54mm. This tire calculator will give you better information.
https://www.wheel-size.com/calc/
If plug in the numbers you get a 9% increase in overall diameter with a 225/55-17 tire. This calculator also gives you information on where there may be clearance issues.

 

With how large the wheel gap on the F-series is I'm sure they'll fit as you'll fill the wheel gap by 1.24" more than stock. 1.24" also happens to be more or less the amount lowering springs and coilovers lower the car. But you'll actually be lifting the car by 1.24" so it's going to sit higher. Your speedo is also going to be off by -9%. Here's what Will They Fit? says.