I wouldn't bat an eyelid at
Jolyon as I know two, and was almost one myself. But I've never come across a
Peregrine outside LOTR, or an
Inigo apart from
Inigo Jones &
Inigo Montoya.
You're dead right about
Demi though - I've seen far too many Demi-Leighs and variants in the
UK baby name charts. It's a horrible fake-Emily name anyway, but what makes it worse is that I think it might have come via tabloids from the name of a child in some sort of abuse case.