I'm with mousethief on this one: "Let her go, and God bless her" is just the sort of thought someone might have in trying to deal with the death of a loved one. And as I've said above, I take the "search" as a kind of whimsical if melancholy fantasy - which is not to say that that business has not been 'imported' from another song, but that those who passed that import along understood it in something of the way I suggest.