If the bags are kept at a good temperature, they should be ok. What you have to be very careful of is not rushing to get them into the tank. I learned a lesson one time when I took my fish, that arrived in the morning, home at lunch and acclimated them only 30 minutes so I could get back to work. Within three days, all three fish were dead. Now I always take two hours to gradually acclimate them and have had very good luck. The longer the creatures have been in the bag, the more important this gradual acclimation becomes because the conditions in the bag become more different than those in your tank with each hour. Getting home at 11:00 PM, you may be tempted to rush them into the tank. Don't do that. Start floating the bags as soon as possible, but don't add the water to the bags any sooner or any faster. Those two hours are very much worth the investment. Good luck with your purchases.
