You can stay in airport for as long as you want. Some have managed to stay for 16days.
You can try too.
After you clear Immigration and collect your luggage, you can stay for as long as you want. However, there is no reason to stay so long since the MRT starts service at about 5.30am and 8am will be the start of the rush hour in the morning if this is a weekday.
Pls check with Meteorite Logistics their opening hours and options outside those hours. If your luggage is roll-on cabin size, you can probably carry it with you.