Nope, you're cutting it too close. You're gonna need either a) a bigger SUV b) a smaller boat or c) more life insurance. For 6X a year, I'd rent a 4X4 pickup rather than mess up your new car. If you burn up that transmission, and KIA sees a tow hitch, they're going to hassle you about it.
The boat trailer has to be at least 700 lbs, if not more. Then, whatever is IN or ON the boat is extra, too, + whatever or whoever is IN the Sportage is extra.
So if you had the boat + trailer + one passenger + gear that's probably 2800 lbs or 40% over your tow limit.
If it was 5 or 10% I'd say fudge it, but this is too much IMO.
And remember, fancy hitches and electric brakes don't increase your tow capacity, only your safety.