If the measurement device were a light year away and were precise enough to “zoom in” and see which slit the electrons went through, what would happen on the final screen?
That level of precision implies technological advancement, that would result with far better equipment to perform the test and measure the results, providing they would be still needed.
I know it sounds like an attempt to brush the question off, but it’s Spherical Cow and/or Newton’s Flaming Laser Sword territory. 😉