Jaya
I did this last year. The hotel was different to the one this year.
With regards to dressing up - it was mixed some did some didn't. I would say it's up to you!
The hotel we stayed at, the dinner was on Xmas eve.
Weather was really warm - in the late 20's.
The group was large - 32. On the "free" day, half the group wanted to site see. The local guide arrange a day
trip to "Casablanca"
Hope you have a good time
Anna