NYE transportation in Bankok centre. (Bangkok)

Hello
I will be going to the NYE party at Novotel and I presume like all big cities the traffic will be chaos.

Is it feasible to take a Taxi ride OUT of there at 1AM. I will have it pre-booked and with a BIG tip as a carrot. The driver is known to me and I do trust him to be where he says he will as I have used him a lot.

But regardless of that it may not be possible for him to get anywhere near the place.

What's your experience?

Thanks
Tom