In heavy saucepan over low heat, add evaporated milk and sweetened condensed milk. Cook, stirring constantly with wooden spoon until mixture thickens and turns caramel in color, about 30 - 40 minutes. Remove from heat and set aside.
Add egg yolks to medium, heatproof bowl, reserving egg whites in separate large bowl. Using whisk, beat egg yolks until combined. Add 2 tablespoons of reserved hot milk mixture to bowl and beat until well combined.Add remaining hot milk mixture to bowl with egg mixture, whisk until well combined. Divide custard evenly among individual serving cups or large serving bowl; set aside.
In medium saucepan over high heat, mix together sugar, Port wine and 2 tablespoons water. Bring Port mixture to boil; boil, without stirring, until liquid forms caramel threads when dropped from a spoon, about 6 minutes, taking care because mixture will be hot. Remove syrup from heat and set aside.
Meanwhile, using electric mixer on high speed, beat reserved egg whites until soft peaks form. Add reserved hot syrup in thin and steady stream, beating vigorously until the resulting meringue is cold.
Top reserved custard with meringue and dust with ground cinnamon. Serve room temperature or chilled.