A 235 width tire will hardly mount any wider onto a 7" wheel than a 225 width. For the OEM 7" wheel width, you're best off sticking to 225.
So if you do purchase a wider 16" wheel (such as 7.5 or 8" wide with the correct offset to compensate,) a 235 width tire will fit fine, but you would not want a total tire diameter any larger than this.
As I mentioned in a previous post, these tire sizes are too large for your car! Yes, it is a bad idea.
It does not.
Refer to this link here:
Alloy Wheel & tyre fitment calculator - it calculates inset, poke, speedo error, tyre stretch and loads more.
www.willtheyfit.com
assuming that you have went for a 16" wheel for your winters, and you've selected the correct size wheels, you want to make sure that the total diameter of your new tires closely matches the diameter of your OEM tire - (approx. 724.3mm.) 225/75-r16 would be significantly larger in diameter than this, and likely would not physically fit into your wheel wells. If they did, it would still be much too large for the vehicle's design.