We hit the same cold snap last October, too, and were very disappointed that it was too cold to swim.
But usually the weather is very nice at the end of October.
We have snow on the ground here in the Chicago suburbs. I know that it will be hot when we are at the BC in June, though, but it feels like a long way away right now.
The pools will still be open. We were at Storm Along Bay in January when it was 67 degrees. There were people swimming, mostly kids, and they still had the pool games and tie-dyeing activities. Sometimes they will close the pool early at night, like maybe 8 or 9 pm, if it is really cold out. But it has to be very cold before they close the pool, since there are always people wiling to swim in cold weather. The quiet pools stay open until 11 pm no matter how cold it is.