Although it's open all over half term the firework displays are only on the 21-22 Oct and 27-29 Oct, so try and go on at least one of those days, as the display is pretty spectacular. Sorry i can't help on hotels as i live near enough to make it a daytrip.
My friend looked at packages recently and said she could get a package for only slightly more than buying the tickets on their own.
PS I'm a newbie but i picked up on your sad news form the other threads, I am so sorry.