There are several.
Swan Bay is VERY nice. New a few years ago. Right on the water. Only a few miles to Alexandria Bay. Paved path to a grocery and liquor store. Pretty much the heart of the 1000 Islands. A stones throw from I-81...easy access.
New York state has several grounds. One not but a few miles from Swan Bay. The one I know best has no hookup sites and power/water only. None have full hookups. Easy access dump stations.
There are others..I'm just not personally familiar with them.
2017 Riverstone 38FB Legacy