How to get to Fuzhou airport for 6 am?

We need to be at Changle airport for 6 am. The Airport Garden Hotel is full for the previous night, and we can't find any other hotels nearby. (We would prefer to stay locally if we could.)

If we stay in city itself, what's the best way to get to the airport for 6 am? The buses seem to start running at 5.30 which is a little too late. Can we get a taxi from the city? Can we book in advance?