Today at about 2 am I have spotted a light very similar (perceived speed and apparent brightness, motion due East) to ISS. At very first I thought to have spotted the station but immediately I doubted about as I feel that the observation time is too far from sunrise. ISS is indeed ruled out as there is not email from the spot the station service in my inbox. Can satellites orbiting at higher orbits be see even in deep night? I feel that answers is yes based on simple geometry. However what could reflect so much light? I think there are not objects with reflecting surface so big to be compared to those of ISS...
If you are in the Northern Hemisphere, it is currently close to midsummer. The Sun is never very far below the horizon in the North, even in the middle of the night. There are plenty of satellites that are visible even late into the night. Heavens Above
Most are not nearly as bright as the ISS can be. However, against a dark sky a satellite may appear brighter. Lots of the objects that are visible then are actually rocket bodies. They often have a higher orbit than functioning satellites.