No point in running them at room temperature. GPUs, etc. run fine at 95 C. If you run your cooling loop at 70 C instead, you get 70% more cooling compared to 27 C.
At any rate, 1 MW for a single satellite is fine. Just launch several thousand of those and you get to real numbers.
Also, there's no need to talk about "magic" radiators. You orient them so they're at a knife edge to both the Sun and Earth. This is not difficult (the Moon is irrelevant).
No point in running them at room temperature. GPUs, etc. run fine at 95 C.
They run fine for a short while, but not nearly as long.
Heat accelerates all aging processes. It's how they artificially age chips in order to calculate MTBF.