[name]Evangelina[/name] is is five, and I think you could easily go by that. Hyphenated names could get into that, for example, [name]Sarah[/name]-[name]Angelina[/name] or [name]Mary[/name]-[name]Alexandra[/name]. I think six is the most, when you get into seven or eight, it would have to be a name like [name]Margaretta[/name]-[name]Maria[/name] or [name]Olivia[/name]-[name]Angelina[/name], and I just can’t picture someone going by [name]Olivia[/name]-[name]Angelina[/name] in full all day long.
It really depends on the person. In general, 3 syllables is fine; I’ve known Christinas, Joannas, [name]Sabrinas[/name], Bethanys, who for the most part went by their full names, maybe using a short-form for close friends. [name]Even[/name] 4 syllables, like [name]Elizabeth[/name], isn’t that arduous to say. However, some people prefer or are more suited to a shorter, 1- or 2-syllable nn.