So you have 2018 points but not 2017 (your current UY), right?
The only thing I think that is "important" to realize about your booking is that you will almost certainly lose any points used to book this trip should you need to cancel since you'd have nearly no time to re-use them by the Aug. 31 deadline.
Do you have any future plans for your 2018 points? If so, you could buy OTU points (up to 24 if you haven't already bought any this UY). I'm sure it wouldn't get you an entire trip but may help you conserve points if you are not wanting to go too deep into borrow mode.
Honestly, if I were you, I'd even consider renting. Sometimes you can get points for SSR for like $8-$9 / pt last minute!