junebuggena
Crowing
Easter Eggers were originally derived from birds that came from Chile. Chile is a mountainous and very cold region of South America.You can remind your Grandma that all those breeds (except the EE, they came up from South America) were developed in New England or (old) England long before there was electricity. They're from hardy stock.
I know folks in the south are always more worried about birds in the cold. Remember, folks in the north keep birds with no heat, where it doesn't get above freezing for days on end.
As long as they have enough feed and water, are dry and out of the wind, in a decently ventilated coop where moisture does not build up, they'll be all good.