Visa free travel will be controlled i imagine and not every thai can afford to travel or get there.I would think visa on entry like thailand would work in europe that maybe what they will do.I know many thais who are married to farangs they visit then want to return to thailand,so overstay maybe not a issue but some mit.
It is too cold for thais in winter some like it some don,t but overall many will visit and come back to thailand