I have reams of info on this, but I'm not going to pull them all up. It's off topic in this thread. You can just look at the maps and find the actual German reports. The routes through Elsenborn were stopped and the thrust redirected through Lanzerath (1st SS). That is why they had multiple Rollbahns - if all got through, good, if some stopped the thrust would be redirected into those that were open. The schwerpunkt was moved west behind 1st SS until that was stopped. That was the last progress they made, thus that is where the main thrust ended.