You're certainly right about the need to move the observer, but I suspect you're wrong about how hard it is relative to building a 150m optical telescope (the largest to-date is ~10m).

Orbital mechanics is a pretty well understood thing, so figuring out how the earth will move over the next 20 hours isn't that tough.

The rest is just making sure you're able to position the 1m receiver very precisely and move it around in a very controlled way. I'm no expert, but I suspect we've demonstrated both in one or more NASA missions already.

Probably super-expensive, but less of a technical challenge than building a proper 150m optical telescope.