Food for thought. HoneyPump has given good advice answering your questions as asked. There are other options if you have any desire to add to your apiary. Now might be a time to consider, there may be as many as 8 or more queen cells formed with the method described. Instead of destroying these queen cells developed and described, you might consider placing one each of these cells in 2 frame mating nucs with a frame with honey and a frame of empty comb, along with a cup of (nurse) bees, (Young nurse bees). If only half of this hypothetical number of queens are successful in hatching and mating you will still be well on the road to 4 more hives. Of course these will need assistance and nurturing but nonetheless, you will be headed in an upward number of colonies.
This will not hinder your plan to order a queen. Go ahead and do so at the proper time. That will give you a hypothetical number of 5 if this one is saved, and you may consider, if the bought mated queen fails, you still have the four mated laying queens in reserve. As I said food for thought.