Add milk, 1⁄2 cup water, salt, and eggs to a blender or food processor and blend on high speed until combined.
With blender on low, slowly add melted butter, then add flour in two increments. Stop blender and use a rubber spatula to scrape down sides of the container. Blend on high for 1 minute. Pour batter into a small bowl, cover, and set aside.
Heat a lightly oiled crêpe pan or frying pan over medium-high heat. Pour or ladle about 1⁄4 cup of batter onto pan, tilting pan in a circular motion so that batter evenly coats surface.
Cook until top of crêpe is no longer wet and bottom has turned slightly brown, about 1 to 2 minutes.
Run a thin spatula around edge of pan to loosen crêpe. Slide crêpe onto a serving plate and place a piece of parchment paper on top. Repeat process until all batter has been used and you have six warm crêpes.
Working with one crêpe at a time, place a piece of feta in the center. Fold sides in around the cheese to create a blintz.
Heat a lightly oiled frying pan over medium-high heat. Place blintzes in hot pan and sear until golden brown; flip and brown the other side.
Transfer blintzes to a deep serving dish. Pour strawberry-honey mixture over top and dust with powdered sugar.