You have not seen many folks off Sand Point because the current is so strong that the ice is very unstable. On rare occasion, there is safe ice to cross to Grand Island to the ice caves north of the lighthouse. Even then, the area immediately in front of the lighthouse is unstable. I have been on shore over there and literally see and hear the water flow under the ice. At 160 deep, I keep my distance in those situations.
There are better (safer) opportunities in the west channel areas between landings on mainland and Grand Island. There is current there, too, but the ice is usually more stable. Even there, be cautious and ask the locals near shore of ice conditions. There was a report last week from sheriff's office warning of open water at a whirlpool west of the landing. Hope this helps.