Six days at Amansara is a very agreeable amount of time to spend there (we didn't think four was enough) and October might well be perfect - the rainy season is ending, everything will be lushly green and there will be fewer crowds.
You are served a mini breakfast at around 6am (usually coffee and croissants) and then you go out with your guide and remork driver. Remorks are motorised rickshaws with a hamper on the back for iced water. We knew the Angkor site from an earlier visit and said we wanted to visit some remoter temples along with the usual ones such as Angkor Wat, the Bayon and Ta Promh. Thus we saw some marvellous places a little bit off the track and very often we had these to ourselves. One morning we went to Angkor Wat in pitch darkness and entered the temple compound from the back and walked through to the front in time for sunrise. We also went out to Banteay Srei which has the finest carvings.
We are temple junkies and take a lot of camera gear but even if you do two tours a day you still have a lot of time at the hotel to laze around and swim. It's not an extensive place, there are no large gardens, but on the other hand it's beautifully quiet and
secluded.
Much of the front of Angkor Wat - the classic view - is currently being restored and is covered under an immense green sheet. It's been like this for at least two years.
About Amantaka - perhaps a slightly better hotel than Amansara and Luang Prabang is a great place to wander around on your own. We stayed 4 nights and though that was about right.