how to get to novotel nathan road from hong kong airport at 11:30 pm with 6 adults and 1 child?

By public bus, I suggest you take bus no. A21 (the last bus leaves at 00:00) and get off at Nathan Hotel, Nathan Road bus stop. Then your hotel is right within 100m away.

By taxi, you need two taxis and it costs 300HKD per cab. If you want your way to be comfortable and you all travel together, you can reserve a limo from your hotel and the charge shall be around 900HKD.