Red plates = not driving after sundown and not leaving your town. If you do have to you should go to the police station and apply for a permitbook in which you have to note down your trip(s) ... this is how it should be done but hardly anybody does it.
As long as you do not encounter any difficulties like an accident nobody will say anything, the problem might arise with your insurance if you haven't followed the rules and got into an accident.
The wise way is wait for your regular licenceplates and just stay in and around the village.
Although your thai family might want you to drive them around so they can show of their red tags ...