I think you might want to ask if such an invasion has any chance of succeeding.
If our satellites were knocked out they could conceivably begin a pre-planned operation where they send small numbers of troops and equipment by air while we are blind. Maybe land some commandos by submarine. Then successively send more and more troops and equipment in following waves. How quickly they could get a significant number of forces to the mainland US is debatable. They might be able to land a significant force in Alaska.
But the main problem with this scenario (for the Russians) is that even if they did start an invasion under such circumstances, it would be doomed to failure. The Russians (or even the previous USSR) do not have enough forces to invade, or a large enough transport ability to project power across the distances involved.
By the above I mean that although the Russians might be able to deliver paratroops and ground forces by aircraft in a timely manner, while our satellites are out, the numbers would not be enough to accomplish anything worthwhile. And any follow-up forces delivered by surface ship would be easily detectable by our Navy and the current incarnation of NORAD. Any forces sent by ship would be sunk by conventional air or naval forces - or if the threat was considered serious enough - by nuclear weapons while still at sea.