Calling before you go won't do any good. It all depends on how busy the pool is, and they won't know until you are there.
If it's anything like it was this past week, forget it. As DVC members we called one day and were told no, as both GF pools were at capacity, same with the Polynesian pools!
I agree with the other poster, have a leisurely breakfast at the GF Cafe or get a spa treatment. You could also rent watermice.
As an FYI--if the front desk says yes the lifeguards can still say no, becuase safety is their responsibility, and they have the ultimate say. So instead of calling the front desk, my advice is to ask to be transferred to the lifeguard stand and ask them.
Anne