Book your hotel room directly with your casino as far ahead as possible.
Check their cancellation policy and you will find that most of the hotels give a full refund on cancellations.
By doing this you will be able to pick and choose a different hotel closer to your arrival time to see if you can get a better deal.
If you are not able to get a better deal, you already have your previous booking made many months before you travel.
I have used this tip and I have, on a number of occasions got better deals.
Go directly to the casino websites to make your booking.
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