I really don't think that it's very do-able. You have to factor in other timesinks such as walking from Changi to the MRT, waiting for the MRT to arrive, etc. Walking from Aljunied MRT to the houses on Lor 20 or so is at least a good 10-15 mins.
The best option, if price is no object is to book a room at the airport hotel and arrange for an outcall. Are you leaving at midnight?