We were just there and I'd say it was between 78 and 80. I'm pretty sure they keep it heated year round. If you're concerned I'd give the hotel a call directly.
I've visited the hotels in winter - February, and there were people in the pool, even though it was kind of chilly outside (by my So Cal standards). I'm pretty sure they heat the pools.
The pools are heated, but not enough for me. My kids were fine with it but they were shivering towards the end. This was over Spring Break a couple years ago. There is an Embassy Suites with an indoor pool, but it's not the same experience as staying at the GC.