What do I need for a visa run to Cambodia from Thailand under the 30-day exemption?

maybe better you go to chaeng wattana on monday (or later if you still have time left on your stamp) because it's likely most outward flights will be cancelled very soon once the airlines realize the only way to get their planes here is to fly in without any passengers, then immigration will have to come up with a solution (and/or the british embassy will start giving those letters).

good luck, i'm flying there tomorrow to get new visa from the embassy for me and my son, hoping for the best and to get back into bangkok

Have you already extended? You can get the normal 30 day extension if not.

Also, I did this in December. They made me spend one night in Cambodia. No in and out.

Cambodia is closed, you won't be able to stamp out.

Cambodia shut ,only laos still open..but need visa to get in from consulate since yesterday..only way