I would definitely go for pool / spa heat in November. Also keep the pool blanket on overnight (helps retain the heat so that it is warmer in the morning).
Always at that time of year. Like Kay has mentioned use the pool blanket when not using the pool. It only takes a few minutes and you will appreciate the results.
Absolutely! We went late Oct/early Nov and it was so nice to come back to a nice warm pool after a long day at the parks. A couple of nights it was a little cool outside, but the pool was like bath water