There is an entire lake here. He could scry in the lake. Of course, the magic would probably be harder than expected, but he never really took into account the size differences with regards to scrying. The spell wasn't designed that way after all. Strange pauses for a moment as he goes through some nerdy theory thoughts before deciding fuck it.

He takes a drink straight from the bottle of sunlight ambrosia, pushes the bottle for Lambert to take, and announces, "I'm going to scry directly into the lake."

The only way to figure out your limits is to test them and so fuck it, lake scrying. Strange starts to walk closer to the lakeshore, assuming that Syrlya and Lambert are going to follow him.