Yes, Hitler gave bunkers a bad name.
I also was just informed by my neighbor that there are now window units that serve as AC in summer as heaters in winter, so that too is in the works. No reason to cool the entire house in an emergency. Truth be told, my wife would b just as happy if we never ran the central heat or air anyway, so I may just control temperature in that one small room with one small unit even when the grid is not down.
I’m glad we had this conversation.