I used to work at a plant nursery. As long as you have a nice chunk of dirt underneath you should be ok. Keep it moist and yea keep the plastic bags OPEN if you can. Heat is your enemy, not moisture inside those bags. We used to keep "sheets" of grass for sale in the parking lot. The grass could survive for a long time in just that half inch of dirt just fine. It's the heat coming off the parking lot cement that was the problem. BTW!!! CHECK IMPORTING PLANT LAWS COMING IN FROM HAWAII!!! I know from experience its very stringent but, honestly I think they're more concerned about bugs and plants coming INTO hawaii.