I think your hotel is somewhere near point 1 and point 15 on that map? The flood will originate from the river so it may be prudent not to stay near the river.

As for the airport run, the most part you will be on an expressway some 8 meters above the ground so I don't think you will have issues getting from BKK airport to downtown.

As for your choice of hotel, I am not going to promise you nothing will happen... Right by the river... The same river that's going to bring the flood waters from upcountry.

They reckon the barriers will hold unless Murphy's Law kicks in and a couple of contributing factors come together all at once.

It has been raining here on and off all week long so if it's high tide and the river is rising and it's pouring down rain, that's when the locations marked on that map may affected.

If I were in your shoes I wouldn't cancel the trip but if your hotel reservation can be canceled without penalty maybe consider staying away from the river.

Let's see what tomorrow morning's news will bring.

Edit: Yeah your hotel is on the other side of the river from 15. So according to the map you would be OK... But you would have to cross point 15 on the risk map to travel between hotel and airport.