What an interesting idea! Since life is not perfect, any representation of it being that way would of course not be truly "representative." For this reason, any utopia is evidently a distortion of reality, whatever the depiction may be.
Whether a utopia is a satire or not is another question. A satire is indeed a representation of something else, but it is usually done to mock an institution or to criticize it by representing it in a humorous (or even ridiculous)way. Many utopias have been portrayed in such a manner (I'm thinking here of Swift's 'Gullivers Travels' or Wells' 'The Country of the Blind,') but others are shown in a negative, serious way, much in the spirit of a cautionary tale. (Lois Lowry's 'The Giver' would be an example.) The tone of the story (light-hearted and humorous or sombre and serious) therefore can be cast either way, depending on the intention of the author and the message he or she wants to get across. In this particular work (Thomas More's 'Utopia'), humour is indeed used to poke fun at both political situations and social issues.