Asteroids aren't that cold, even. If you had a ship with a deep parabolic shield, the outside of which absorbs EM radiation and the inside of which is highly reflective, the ship could be rendered invisible outside of a narrow cone where it's directing its waste heat. It would still occlude starlight, but unless some of the enemy's sensors are stealth platforms, false signals could be generated to prevent the occlusion.

Such stealth ships couldn't maneuver much, but they could only be countered by other stealth platforms in a cat and mouse game reminiscent of Cold War submarine contests.