I buy all my water premixed, it's about 65 degrees from the store, I usually heat it before I do a water change. On my 3 gal not so much on my 5 gal I do for sure.
My plan of transporting the fish was....
2 clowns in one bag
BTA in its own bag
6 line wrasse and mandarin in a bag ( I think I'll have enough left)
The finger leather will have to go via bucket, and I'll probably take most of my corals this way.
It's about an 8 min drive to my LFS, 12 if I get stuck by the 3 traffic lights in town.