October, and April - are borderline months. Some would get pool heating and others not.
For example we haven't pre-paid heating for our April holiday, but have an 'agreement' with the owners and Management Company that if we decide to go ahead we can do so out there and pay $ in cash at the time.
If you opt to not book heating most villas these days come with a pool cover, these can help keep the heat in when the pool is not in use.