Size does matter

There is no straight answer to this. It depends on the ride height. 26" should be ok in general.

If you are willing to shim the front shackle, which is very little work to do, you can run at least a 28" tire, even with a lower stance.

In regards to the 4x4 stance, which I'm happy to see is starting to fade away, lowering blocks take car of this easily. SO you can compensate for the added ride height the taller tire causes.