We drove Korat to Udon yesterday and the traffic was horrendous. Take your time and overnight if you have to. We left at 5am therefore far less traffic to start our with.
Make sure your destination has liquor available when you arrive
Good luck
I had blood in my stool and a screening was suggested. I had it done in Udonthani and eventually they confirmed that I had cancer of the Colon. By the way they DO NOT PUT YOU TO SLEEP for an MRI.