I just did this exact same thing about March 1. Have your wife with you and your marriage certificate. If they ask say you are applying for a marriage Visa. That's what I did and no problems stamped in for another 60 days
For the past year and half I have been staying in Thailand 3 or 4 months and going back to America for a month or so and coming back. I never have had a problem. I have gotten married now and going to America 1 May and will be coming back on a non O visa when I return
I live in Khon Kean and when I had to make border runs I would just catch a train to the border with Laos and cross spend the night and catch the 1250 train back