If you have some baggage you can take the airport rail to Makkassan station and get a taxi from there. if you don't have too much then go Phaya Thai.

I've been stuck in BKK traffic many times but I've never not moved for 45 minutes. I doubt it will happen again but do the same thing you did last time if it does.

If you have a lot of baggage, take a car or taxi and take your chances.