@George ******
you're 4 hours and change from the Phu Nam Ron Border crossing with Myanmar in Kanchanaburi and you're 6 PLUS hours from Nong Khai ;)
I'd say bounce out and back in for a 30 day visa exempt entry (as long as you don't have TWO 30 day visa exempt entries this year) OR are activating a new entry on a multi-entry visa at The Myanmar border.