That time of the night should be really busy. Unless you can get a "fast track" pass, expect at least 30 minutes to clear Immigration. Also,if you go anywhere needing a taxi, expect to wait 30 min in the taxi queue.

To collect your bags you will need to clear Immigration. Going back through immigration may well take another 30 minutes. (yawn)

The airport Novotel is right next to the carpark as you exit the terminal. The suggested "by the hour" hotel would be a better option. Even better would be paying to get into the PP lounge. This will mop up time if the inbound flight is late.