[noun] + に限る [verb (dictionary form)] + に限る [verb ない-form] + に限る
に限る says "nothing beats X", "the best thing is X": the speaker's firm opinion, usually from experience, about what to have or do in a situation. It follows a noun, or a verb in the dictionary form or the ない-form, and the situation usually comes first with は or ときは.
The verb before it is never in the past, even when the opinion comes from what happened to you: ×寝たに限る.
In notices and rules, に限る keeps the literal meaning of かぎる限る: something applies only to the noun before it. The form にかぎり限り does the same in mid-sentence: ほんじつ本日にかぎり限り, "today only".
にかぎって限って and にかぎら限らず are separate grammar points built on the same verb.