Considering driving to Chiang Mai from here instead of flying. I'm told its normally an 8 hour drive...but can I even get out of town now and how long will it take me to get up there?

The Department of Highway maintains updated highway maps to help motorists avoid flooded, impassable routes.

The map: http://maintenance.doh.go.th/bypass1.jpg

Instruction for motorists: http://maintenance.doh.go.th/map.pdf

[Translation: Bkk to CM: Take Don Muang tollway toward Bang Pa-In (expect very heavy, slow-moving traffic), then take Asian Highway and proceed to Ayuthaya to Ang Thong, Singburi, Nakhon Sawan. And you're out of flood-hit zone.]

Good luck. Let me know how it goes. I'm planning a trip to CM later this week or early next.