Yes, I fully realize this is more than what the Crosstrek is rated for (1500 pounds). But I only have to do it twice a year, once in the spring to take it out to our lake (moored there for the summer), and then pull it out in the fall. It is only about 50 miles distance and no big hills.
I have actually pulled this same boat/trailer in the past with my old Legacy wagon (135 hp), and it handled OK. Of course I drove very carefully and made sure I didn't follow anyone too closely. The trailer does have surge brakes. Biggest concern always was being pulled over by a cop, as that car definitely looked a little small in front of that boat. But the Crosstrek is a lot taller, so hopefully won't attract that attention.
Having said all that, I would still prefer the Ascent, for that and other reasons. But I just don't know if I can wait that long.