Forget the tents. Put them right on busses and ship them back to the border. Do not pass go.
You put them in buses, they are back by the end of the week. They spend the summer in a tent in Texas... well, they just may think it over. They spend a winter in a tent in (northern) Texas, they won't come back! BTW, while in the tent cities they could be made to work to pay for the "room and board" so that would not be a concern.