I would not go wider than 215. Any wider, and you're going to have to put steering rack limiter. The other thing too, the 225/45 would have a slightly smaller diameter which means your speedo will be out, that is, it will be overestimating your speed. There is already a slight overestimation of speed with the standard tyres, it will be worse with the 225/45s.
Check out this site:
https://www.tyresizecalculator.com
It has various calculators for resizing tyres.
As I said, I would not recommend going for a bigger width because the standard tyre is right on the limit already.