I realize you want to know the max and not everyones opinion. With a ridiculous amount of searching to find this information(which isnt much) I will supply you with what I do have.
You can go as large as 20's if you want, it is all about having the proper offset to make this work. If your offset is to low, say + 50, you may not even be able to put the wheel on the hub to bolt it on. The wheel/tire would hit the strut and it just wouldnt work.
Now, if you go with a higher offset like +35, you can fit many wheels up to 20's on there.
I will tell you what I have found to be a comfortable(within reason) size wheel and tire for the camry from 97-01.
18's for example will fit, but only if the rim is 7 or 7.5 inches wide and the offset is between say +35 to +42, 42 is questionable, so +40 would be more where you would want to be.
That applies to any of the other size wheels. You get to wide and the offest to low, you will not even be able to put them on. Or if your offset is to high, you may get the 8 inch wide rims to fit but the outer wall of the tire will rub on your fender.
Keep searching and reading. Here is a thread that will help you some, but You may gain more info from my post, either way, read up, it will help.
Lets Talk offsets !!! my friends
Mattster