Short answer:
You're fine, as far as the awd system, running it anything less than semi-permanently, even a few hundred miles if need be. The biggest consideration in that circumstance would be that it's not a matching tire so emergency handling may be compromised.
Long answer:
Tire size calculation puts the difference at .3 inches of diameter which is the equivalent of 5/32 tread depth difference if all tires are new. That number is at the outer edge or perhaps slightly outside of what is considered an acceptable difference by Toyota, however I'm aware of no explicit Toyota statement on the matter. I base it on what is implied by the same side tire rotation recommendation that applied to the 4th gen, too, but where the spare was also expected to be rotated in on one side. If you do the arithmetic on how much difference there could be in tread depth between the tires on opposite sides at the end of tire life, it's in the ball park of 1/4 or 4/32nds. This 4/32 number appears in other places, as well, when searches are done for various AWD systems and their tolerance to differences in tire sizes. And to state the obvious, as you wear down the tread on the in-service tires, the difference will shrink over time.
