Lets assume an electrical consumption of 1 MW which turned into heat and a concommitant 3 MW which was a byproduct of acquiring 1 MW of electrical energy.

So the total heat load if 4 MW (of which 1 MW was temporarily electrical energy before it was used by the datacenter or whatever).

Let's assume a single planar radiator, with emissivity ~1 over the thermal infrared range.

Let's assume the target temperature of the radiator is 300 K (~27 deg C).

What size radiator did you need?

4 MW / (5.67 * 10 ^ -8 W / ( m ^2 K ^4 ) * 300 K ^4) = 8710 m ^2 = (94 m) ^2

so basically 100m x 100m. Thats not insanely large.

The solar panels would have to be about 3000 m ^2 = 55m x 55m

The radiator could be aluminum foil, and something amounting to a remote controlled toy car could drive around with a small roll of aluminum wire and locally weld shut small holes due to micrometeorites. the wheels are rubberized but have a magnetic rim, on the outside theres complementary steel spheres so the radiator foil is sandwiched between wheel and steel sphere. Then the wheels have traction. The radiator could easily weigh less than the solar panels, and expand to much larger areas. Better divide the entire radiator up into a few inflatable surfaces, so that you can activate a spare while a sever leak is being solved.

It may be more elegant to have rovers on both inside and outside of the radiator: the inner one can drop a heat resistant silicone rubber disc / sheet over the hole, while the outside rover could do the welding of the hole without obstruction of the hole by a stopgap measure.