I think it is a bad idea to lease beyond the bumper to bumper warranty. 2 years and 15,000 miles is perfect, in my opinion, assuming the payment is about the same or what you are comfortable with.
Here are the numbers for 2016 Forester 2.5i Premium CVT…
36/15K: 60% residual, .00090 MF
From plugging in those numbers into the lease calculator, I get roughly the same results, so no red flags here. Subarus aren’t discounted much; the dealer discount of $2,300 off MSRP looks pretty solid.