The Eibsee cable car will no longer take anyone before the first official ride at 8:00 am. If you were lucky, they would take you on the revision ride, or when taking up the people working at the summit, but apparently they don't do that anymore (they never did officially). So don't count on it. I'd rather sleep an hour longer.
You will also want to check if the cable car from the Osterfelder is running at all. It usually does during skiing season, but depending on snow conditions, it may not.