Correct, but it depends on whether the cloud is BKN, OVC, SCT etc as to whether it could cause a problem, I've approached many airports where the cloud base has been 100ft and still got visual at decision altitude. At night it's alot easier to "see the lights".
The forward visibility is irrelevant provided you have the requisite 550m, again I've had 10k visibility with the cloud base at 100ft and gone around and as above I've had 550m with a cloud base of 100ft and got in.