Make it a 2 week vacation. Leave early, come back late.
Several years ago I went to Mukdahan during Songkran. I live in Ratchaburi. I went a few days early and had no problem. I thought I was leaving late enough after Songkran. I was wrong. It took 13 hours to drive from Mukdahan to Saraburi. Then finally it cleared up enough and only took 3 hours from Saraburi to Ratchaburi, it was after midnight then.