As you've noted, in the U.K., the two spotted Ladybird (they're known as Ladybugs here in the U.S.) is the most common, while here in the U.S., the most common is the seven spotted variety. There are about 500 subspecies in the world ranging from no spots up to about 24... By, the way, try not to disturb them while they hibernate. To do so risks exciting them and having them release a yellow, sticky, smelly fluid (it's actually their blood and harmless) which stains painted surfaces badly...
(Hiya, Cetti)