With the 2 older kids, I'd probably recommend looking at the Wyndham Bonnett Creek timeshare resort at the same location. Odds are you could manage a 2-bdrm unit cheaper than what you'd end up paying for the Grand. (Remember, the Wyndham Grand has several additional fees on top of your nightly room rate, including a self-parking fee and daily resort fee).
The 2bdrm condo would definitely give you more room (and a 2nd bathroom/shower) than the bunk bed suite, and you'll still be able to access most of the hotel's amenities.