Elven (Re-)Marriage - "Till death do us part"?

[Estelyn Telcontar]

The interesting topic of elven marriage and remarriage came up on the chat a couple of days ago - how does immortality affect the validity of marriage? Here's what we discussed; perhaps someone can add insight to the questions we had.

zifnab: In Elf marriage, say that a strappin' young lad marries a beautiful vixen, he goes to war, and dies. Will he await her in the "Undying Lands", after the Halls of Mandos? Or does the relationship end at the moment of his death?
Estelyn: I see what you mean - is there a "till death do you part" for the immortal elves?!
Estelyn: Does anyone know of remarriage of any elves?
Estelyn: Wait a minute, Feanor's father remarries!
Estelyn: He has two sons from the second wife!
zifnab: Yes, Miriel dies.
Estelyn: So is marriage not immortal for the elves?
Voronwe: I think he was only allowed to remarry if Miriel remained in Mandos until the end of the world
Estelyn: Now I haven't read everything - do you know of any other remarriages by elves?
Voronwe: I don't think any other elves ever remarried
Estelyn: So is the marriage of elves immortal as they are?
Estelyn: no death = no parting
zifnab: So it seems.
Voronwe: Although one of them can 'die' and go to Mandos
Estelyn: ...and why the exception with Finwe??
zifnab: Maybe like V said, that Miriel was "fated" to stay in Mandos, or some other reason nulled out the marriage.