How do you scale without wiping what the ad has learned?

You scale by raising the spend on the campaign that already brings bookings, a little at a time, without changing the dish or the radius. It is not duplicated into a new campaign if that forces the learning to start from zero. The campaign is copied, the text is changed and the next day the spend goes out with no bookings. The same campaign with the new cap noted and the date it is looked at again.