Dunn v. Blumstein (disclosure: found it through Wikipedia) creates strict scrutiny for durational residence laws (on equal protection and right to travel grounds). I’m assuming the same principle would apply to requiring a domicile. I don’t think the state interest passes strict scrutiny, because of the cases that have been brought up here. As for the second point, disenfranchisement is possible, since there’s certainly no requirement for New York to allow people to vote there just because they have not lost their New York domicile.
