Tank Build! Been a long time but diving back in. 180 gal build

That's no good. Part of the risks that come with ordering this time of year. A weather delay for a day in this kind of cold is A likely death sentence for livestock. Those heat packs are only going to last so long.
I think fish do better with too cold as opposed to too hot, but they can still only handle so much swing and stress.

 

Just an FYI and something maybe to watch if you are looking at weather windows for shipping. The regular live aquaria livestock comes out of a wholesaler in CA. The divers den items come out of their facility in WI. The divers den stuff goes through more of a monitoring and quarantine process than the general stuff. Neat facility up there if you ever get a chance to go on one of their open house tours.
Either way, as you said, live aquaria is easy to work with and does guarantee the livestock.
Another option is go for a road trip and hit some Iowa stores. Then you don't have to deal with shipping and can see the specimen before you buy.