chaliehall: In NY, you can vote in any jurisdiction in which you have a residence, but you have to choose which one. This has become contentious recently as largely Republican upstate towns have been trying to disenfranchise largely Democratic vacationers.
Similarly, in Sullivan County some local politicos and the local Board of Elections have been disenfranchising summer residents who wished to vote there, instead of in their NYC residence. Like you’ve stated, New York state court precedence allows any New Yorker to vote in any jurisdiction in which he has a residence, including seasonal. (As long as that is his only voter registration.)