Try to keep them about 60 degrees and store large end up. I keep mine in an egg carton, I don't have anywhere to store at 60 but I keep my house about 73 so I just set them in a cool dark corner. I usually will turn mine back and forth in the carton until I set them in the bator.
I keep mine in the dining room in an egg carton. Mother hen does not check the temp.
As long as it is cool and dry...meaning not hot. Outside in the nesting boxes, even in the heat of summer, it is pretty cool, or even a nest in the garage ( I have found eggs there) kept them fairly cool. I wouldn't worry about it unless you are in a 90+ heat zone. Go for it and good luck.
Oh, yes, listen to lockedhearts about how to put the egg in the carton, sorry, I forgot, pointy end always down.