Not Castaway, but we were once on a different resort when the weather was similar - low 70s, decent wind all day, and a little drizzle. We had a cabana and thought it was great. It was nice to have a "base" and the cold didn't keep the kids inside. It was 5 degrees when we left home so 70 was still pretty darn nice. We stayed the entire day, so if you're going to make use of it, I'd say it's worth it. The people in the next cabana, however, were bundled up in full clothes, hoodies, and towels, and just stared at their phones the whole time. Literally, every time we walked by, they were each curled up in their own little balls staring at their phones. I really wondered why they had wasted the money on the cabana when they could've been doing that anywhere else on the resort, with climate control.